Every time i play a rally event (so far that's the only event where I've had this issue), the game locks up on the loading screen after the first race.

I've done everything on the Microsoft Xbox support page barring requesting a repair as its not an issue with my console because it only happens with this game.

I've also contacted Codemasters about this but they just keep directing me towards the MS support page despite telling them that I've tried it all several times

Has anybody else has this problem?

There was an issue where the game was known to "soft lock" on the loading screens during races if you had the 360 Guide up, but I believe that was patched... maybe. So it could be something different.
 
If the game isn't installed, install it. If it is, remove it. E-mail Codemasters? Clear the memory cache? Tweak some of the options?

it must be something different because it only locks on the loading screen after the first race of a rally event, all other events run fine

ive tried all the usual fix's but its still happening, and codemasters so far have been no help

IIRC it was the same when it happened to me. It would always be after I had completed something and during a loading screen, but only ever when the Guide was up. It hasn't happened in a long time, but I haven't gone back to any of the Dirt Tour races. Did it start happening only after the title update?