Firstly I need a little clarification on what might cause my video card to heat up to 100 degrees C. I've never noticed any problems until I started using a 1080p capable monitor, could running games at 1080p resolution be contributing significantly to the overheating issues I am experiencing (It appears the fan is running fine)? I know my computer could use a little more in the way of cooling but this problem seems to have come out of nowhere.

Secondly I am planning to upgrade in the near future and I am looking at purchasing an AMD 6850 (I have been unhappy with my last nVida card I am changing teams). This card seems to have Ok performance and is within my price range (Hardware can be expensive in Australia). Does anyone have any experience with this card with regards to value for money.

I assume you've cleaned the box well (get rid of dust), made sure there is enough space for the outflow of air and updates to the latest drivers?

I've found my 2X0 series cards always ran very hot. It's one of the reasons I switched to a ATI 5870. It runs much cooler, makes almost no noise, and has 6 outputs.

Have you cleaned your card's heatsink? Checked to make sure you don't have cables obstructing airflow? Checked to make sure the fans are still spinning?

Check for dust, and if you don't have any case fans, you're lucky it hasn't melted on you

Have you tried downgrading the resolution to 720p or similar?

Which GTX295 model?

I would try disassembling the cards cooler to remove all dust. It could be that your case appears fine but within the card itself you have a major build up.