Thought I would throw this up as it's nearing the North American release of Fifa 10. I didn't compile this list but if like myself you were looking forward to Fifa 10's new and apparently improved manager mode you may wish to think again. 
 
These are the found bugs so far, personally I've experienced say roughly about a third of them myself but EA's forums are pretty heavily hit with complaints at the moment.
 

LISTED IN ORDER OF SEVERITY

1) The Manager Mode freezing bug (where you can’t progress without your console locking up) still occurs, usually preceded by this error. [SCREENSHOT]

2) It has been reported that with some people transfers “lock” altogether after a certain amount of seasons (being linked to a disc problem). [INCIDENT 1]

3) All teams below the Premier League have their tactics set to all-70s. Applies to other leagues/teams as well, see Australia, Brazil and others.

4) All assists are credited to the goalkeeper.

5) Players you loan out can be sold by the clubs you loaned them to.

6) Newly signed players vanish from your squad with no warning. They just disappear, and then if you look them up they’re playing for someone else.

7) When trying to sign a second loan player, sometimes I am told by the game that I already have two – when I only have one.

8) When signing two loan players, I then tried to (permanently) sign two free agents, and I’m told I can’t sign them because I “already have two players on loan”.

9) 90% of matches in England are played at night in the rain regardless of stadium choice. I’ve yet to see a match played in the daytime with sunny weather.

10) Seasonal changes don’t seem to affect the weather. So in England, in the summer, you will see rain and even snow with no games being played in sunshine.

11) Signing players is practically impossible, even when offering maximum wages and maximum bonuses, even if you can get their interest level up to 85%+. (Even if you start out as a manager with no reputation, you should be able to sign really poor players with no reputation who aren’t getting first-team football elsewhere.)

12) Signing your own players is just as difficult, regardless of how well the team is doing. They refuse to sign even when you offer the maximum wages allowed. But if you wait until the end of the season, you get the same screen you get in FIFA 09 where you can just tick a box to re-sign a player and they will sign for peanuts! Strange one!

13) The board sack you even if you occupy first place. You can expect to be fired at the mid-way point of the season if you lose a cup game, even if you’re in the top four of the league, especially in the Premier League. Even in the lower leagues, I’ve seen situations where games are won 6-0 every week for months and suddenly you’re fired the moment you draw 1-1.

14) When playing against teams who are better than you, your board always expect you to beat that team. I mostly play as a League 1 team, and if I’m beaten by a Championship or Premier League side I get a board comment that states I was “expected to win the game”, and occasionally you will get the sack for this. This may be because teams aren’t recognised in their correct division; for example, when losing against a team from the league above you, you will occasionally get a message that says you should have done better against “lower league opposition”.

15) The assistant manager, even when turned off, will swap your players around when you buy or sell a player. Player roles are also reset.

16) The assistant manager AI is terrible. It will choose players with no fitness (10%-20%) to play out of position, over players with 100% fitness who can play in that position. See below for more info.

17) The AI management of other clubs is terrible. Examples; Chelsea play Terry at LB with Cole at CB in the same match, Man Utd play Vidic and Ferdinand as LB/RB with Brown and Evra as CBs in the same match, Giggs gets played at LB occasionally, etc. etc. etc.

18) The effect of form is far too severe. It makes your team go up/down by a whole star rating within a few games, so with a 3 star team you can yoyo to 2 star and weeks later 4 star.

19) The form system seems to be totally random. I can win 2-3 games in a row by 2-3 goals and the form will get worse. A striker can score six goals in a game and his form will DROP!

20) I’ve seen one injury in two seasons; Marcel promised this lack of injuries – and especially this lack of SERIOUS injuries – was fixed for FIFA 10. This is simply not true. The most widely reported injury is whiplash, which isn't a common injury, and which only affects the player for a week.

21) Injuries don’t last for a long enough period of time. For example, a hamstring injury should keep a player out for a month – in FIFA 10 it’s a week.

22) When playing in the snow the ball used is white, which is incredibly difficult to see, and you can’t change the ball yourself.

23) Only 5 benched substitutes are allowed in FIFA 10 below the Premier League. All English league and cup competitions now allow 7 substitutes in reality.

24) Friendly games should allow 12 substitutes on the bench (and also you should be allowed to use all 12). Currently it’s restricted to 7 on the bench (with only 3 substitutions allowed).

25) Friendly games include matches against teams in your own division. This doesn’t usually happen in reality.

26) FA Cup games and the Community Shield game are played at night when they’re only ever played in the daytime now, including the final.

27) The shortlist was supposed to allow up to 20 players to be stored, but seems to only allow 10 players.

28) The overall rating of a player changes before/during the game. So if one of my strikers has an overall rating of 83 (including his form), when I pause the game and go to Team Management his rating can drop by 10+. What value is actually being used by the game? The pre-game rating or the paused-game rating?

29) Form should never affect physical attributes. For example, a striker who is on hot form wouldn’t see his pace increase.

30) Playing as a League 1/2 team, you have literally no fit players left after 3-5 games of the season. I don’t care how bad your fitness coach is, a group of professional players would have enough players fit to start a game after 3-5 games of the season. (You’re forced to spend £1m to upgrade your fitness coach to a realistic level.)

31) The league table that shows up at the start of each game is never correct (same as FIFA 09). It always shows you in 6th-9th position regardless of whether you’re in the top half or the bottom half of the table, and your opponents are shown in an incorrect position as well.

32) When simming games instead of playing them, two things to note. Firstly, the level of your fitness coach isn’t taken into account, so the players lose 25%-75% more fitness than they should. Secondly, when simming, you actually get to see some injuries! Plus they last for a decent period of time (e.g. metacarpal fracture, player out for four weeks)!

33) When you have a player injured, the game forces you to remove him from your team before going to the pre-game screen. You don't want to remove him from your first-choice team, you want to remove him at the pre-match team management screen, like in FIFA 09. But now you can't do that.

34) Often you are not told why a player has refused to sign for you. No explanation is given on the Negotiation History screen for these players and it seems that they are never permitted to sign for your club, for no apparent reason. You never get an explanation for the affected players.

35) Sometimes when trying to sign a player they’ll say e.g. they get a “bad vibe” from your current players. Try to sign them again next week and they’ll sign for you. Doesn’t make much sense.

36) You can list a player for sale/loan who is garbage, e.g. 42 overall when the rest of the players in your squad/division are 60+, and instantly you get offers from the top teams in your division/country for him. Sometimes even top-flight teams from other countries make an offer; they have no possible reason to loan in a player who is literally twice as bad as any other player they have. It seems that every player you ever list you MUST receive an offer for, even if they are terrible, and it’s always a good team that has no need for a poor player which shows interest.

37) As a manager with a reputation level of half-a-star, you sometimes get comments from the board that “a manager of your calibre should be performing better”.

38) You lose respect with the board when losing a game on penalties. You should be given the same increase/decrease you would be given for a draw rather than a win/loss in these circumstances.

39) The leader of the assist list seems to be the player who keeps the most clean sheets.

40) Players who are substituted show no ratings at full-time. So if my striker gets a hat-trick and I substitute him, his rating is blank after the game. (Yet substituted players can receive Man of the Match awards, so a rating must be getting calculated by the game? I presume they’re just not being displayed?)

41) Goals/assists that occur in cup competitions, e.g. the FA Cup, aren’t counted in the player’s statistics. Also goals from the Charity Shield game aren't counted and yet the game itself counts as a game played.

42) When scouted players are presented to you for purchase, they are always said to play on the opposite side to their preferred foot. For example, a left winger will always be shown to prefer their right foot. Yet if you buy the player, most of the time, they will actually prefer the appropriate foot.

43) Some players will sign for a club and then the next week they’ll have signed for somebody else!

44) When searching for players their form ratings are displayed, rather than their actual ratings. This means you have no idea what the player’s actual ratings are.

45) When buying a player, they are given a squad number already in use, and it messes up the squad numbers for the entire team. Why can’t they be given a number that isn’t in use?

46) A stadium will never fill up with people. I can play a Champions League match against a five-star team and all stands will still have large empty sections.

47) The player search parameters you input will reset when bidding on a player. So if you search for e.g. a defender, CB, rated 50-60, playing in League Two, then you bid on one and you want to search for a midfielder with the same rating, the parameters have been reset meaning you have to input each one again.

48) Occasionally the wrong stadium picture is displayed pre-game. For example when playing at the Emirates a picture of (what looked to be) the training ground was displayed.

49) Creating a player (not a Virtual Pro) to sign in your Manager Mode career seems incredibly difficult/buggy. If you create a player and assign him to the free agents pool, the game freezes. If you assign him to a national team, he doesn’t show up as a free agent in Manager Mode. If you assign him to a national team and THEN move him to the free agents pool, you won’t be able to find him anywhere but in the “Created Players” section and you’ll see that his assigned team is referred to as something like "team1932as12309" – you can’t then find this team/player in Manager Mode to sign the player.

50) Commentary gaffes happen every 1-2 games, e.g. “5 minutes to go and they lead 1-0” when it’s 1-1, “I have to say he’s on one of the worst runs of his career” when he’s already scored in the match you’re playing, etc. etc. etc. and also, when playing as your Virtual Pro, you find the commentary refers to you scoring your 20th goal every time you score once you’ve reached that point. So for example when you score your 21st goal the commentator will say it’s your 20th, etc. (not sure if this only applies to Manager Mode or other modes as well).

51) People playing as League Two teams (e.g. Bury) are reporting that they are not entered into the English league cup competition.

52) People are reporting that they can go from having millions to spend to being BILLIONS in debt. [INCIDENT 1]

53) For the new season it was said by the development team that you receive new transfer funds and a new wage budget to reflect the new income for that season. People are reporting they start the new season with the same money they ended the last one. [INCIDENT 1]

54) In the Squad Management screen before a fixture, set it to display the OVR rather than fatigue bar, then select a reserve and swap him with another reserve. I've seen both of their OVRs change.

55) The Edit Formation screen is buggy. If you nudge one position around, then go to change the role of another position, it thinks the second position is where the first is. Sometimes it'll move it so they overlap, and you have to drag it back to where you want it. This was also the case in FIFA 09.

56) The OVR number disappeared from a player's bio. It used to be next to the player's list of positions. Why has it been removed?

57) Your board can give you an objective, e.g. avoid relegation, but you're given no indication as to where the relegation zone is, e.g. playing as a Polish league side the board objectives for the first season are to get to the QF of the cup and to "aviod the relegation zone". Where is it? Bottom 3? Bottom 2? I'm in position 14 out of 16, how are we supposed to know if that's safe?

58) The board will often tell you to invest in new players, when the transfer window is closed and there's nothing you can do about it.

59) When saving a Manager Mode game, when it's finished saving, why are you prompted to save your profile as well? This is with autosave turned on!

60) The Belgian league is missing playoffs.

61) The new Europa League format is not in the game.

62) Incorrect teams make it into European competition. As someone has said, "I got 4th in career mode but a team that ended up 12th goes to europa league while I don't". [INCIDENT 1]

63) For some reason only ten characters are permitted for first names and surnames now, when this wasn't the case in FIFA 09.

64) Friendly games (possibly Community Shield and cup games too) are counted as league games on the Manager History screen. So the recorded points/league position is false.

65) CPU substituted players remain on the field. Example; playing as Blackburn against Bolton, they subbed Kevin Davies for Elmander and you see the animation of him going off - couple of minutes later you notice he's still on the pitch and nearly scores a header.

66) Players sent off after 30 minutes can still win the Man of the Match award, which is ridiculous.

67) Teams from lower English leagues are appearing in European competitions which they shouldn't be eligible to appear in. [INCIDENT 1]

68) Some people are experiencing an issue where the transfer window is listed as having "one week left" when there's actually e.g. four weeks left. Also in some circumstances the transfer window continuously says that there is "one week left" and it gets stuck like this forever.

69) This has been reported by a Manager Mode player suffering from the transfer window bug where the game says there is "one week left" when there are actually e.g. four weeks left. "I put players up for sale until the message came up that said the board will not allow you to sell any more players. I left it at eight players, and now that the transfer window is open, none of the players are set as for sale and I get that same board message as soon as I try to list a player. It's like it remembers I listed the players but it forgets it took all of them off sale itself."

Yeah, it's sad that there is so many issues. Hopefully EA will patch all of them out. Or rather, it's pretty sure they will patch most of them out.
 
I am almost done with my first season, and I have decided to wait and see if I have to start all over when the patch comes.

Wow I'm glad I did not buy it
maybe if the price drops and all that you listed is fixed

I feel your pain... 
 
The main game is fine enough and I welcome most of the changes.

I have a problem with my Virtual Pro in that i'm at 84OVR but the game won't save any further accomplishments I get... Very frustrating. Any of you ever encountered this problem?

The keeper AI is terrible aswell. You want easy goals or corners. Cross the ball in near the keeper, they will screw up most of the time. Also its happened to me a few times where a player will get sent off but he will stay on the pitch. fifa 09 is a better game, stick with it

I have FIFA 10 a while now. I experienced a problem 2 years running in my manager mode. I am Hull City. I made it to the Champions League Final one year and as I went to "next match" a pop up told me I didn't have a full squad available, even though I had 11 players starting plus a full subs bench and all were fully fit with no suspensions. I tried everything that I could possibly think of but to no avail. I was forced to forfeit the match in order to continue to the next season. The next season I changed the difficulty level to World Class and continued with Hull City. Coming to the end of the season, I ran into the same problem again. This time I was choosing my team for the Champions League 1/4 Final 2nd leg against Arsenal. I had no problems with picking my team for the first leg so I have no idea how I can continue without forfeiting once again. Is it possible that a team like Hull City can't win a European competition?? Has anyone ever come across this problem also?? If so, could you please tell me how I can overcome it or how this happens??

I have to say that I'm having far more fun in 'Be A Pro' mode than Manager mode these days, just yesterday I was playing as my local team (Wellington Phoenix) and sold a bunch of players to make sure I stayed at the one star rating (achievement) - so I spent all my money on the fitness coach, continuously through the season each time I had enough... and still at the end of the season I'd go into the next game with half my team down to the red in their fatigue bars... with an 8/10 fitness coach I'd expect my team to at least be in the low green at the start of a game.  Then it seems that each time a month rolled over my whole team was back to full fatigue bars, even though it was only a couple of days since the last game played.
 
So yeah I got the achievements I wanted, am sticking to Be A Pro now - at least in that mode your chosen player has most of their fatigue bar  when you start a new game.