ATI radeon 4870 help

ok, i have been having problems all the sudden with my ATI Sapphire radeon 4870 (1 gb) gpu drivers. I have just recently played through crysis, and i didn't have a single problem until about the 3rd to last mission... Crysis will randomly stop working and a window pops up and says, your video display drivers have suddenly stopped working, but have fully recovered, and windows cant find a solution to the problem, and then it kicks me out of the game. I know my computers not getting hot, and i have the latest drivers installed... so whats the deal here? they worked for 3 days, then all the sudden they dont want to work at all...
any help would be great...
system specs...
-NZXT Nemesis Elite case...Black
-MSI P45 PLATINUM Intel p45 chip set
-CORE 2 QUAD Q9550 2.83Ghz
-Windows vista H.P. 64bit
-8GB G-Skill DDR2 SDRAM 800
-610W PC power and cooling PSU
-1TB hdd (will buy at least one more in the future, and set it up in a RAID 0)
-30gb OCZ SSD which has the OS on it
-GPU, a Sapphire 1GB GDDR5 256-bit HD Radeon 4870
-Lite-on blue ray drive..

That is NOT the solution.

Strange? The 9.1 drivers work great for me.

Well, I haven't tried any games or the 3DMark06 test yet to stress the system... so it could very well not work under stress.
I'll do some benching tomorrow to see. I think what you have in the system itself could affect it too.

Did you use driver cleaner in safe mode before installing the new 9.1 drivers?
That can make a difference.
But yes, if the old drivers work good... keep them. They're not that old. LOL.

They have more than one, but here is one:

Driver Cleaner Pro v1.5
Driver Cleaner Professional helps you to make your computer more stable and usually also faster. When you uninstall or install new drivers for your graphics card, motherboard, soundcard and such there is often registry settings and files that do not disappear as they should. In Driver Cleaner Pro database is saved the files and registry settings that each part, like soundcard, of your computer uses. When you use this program it cleans those files and registry settings and when you install your new drivers you can be sure that your hardware uses the most recent files, registry settings and such.

http://www.afterdawn.com/software/ [...] er_pro.cfm

I dont think that was it, i never noticed the card getting over 66 C... but now im using the 9.1 drivers and after i used that driver cleaner they run very good, i have only gotten them to fail once in crysis, and a few times in fallout 3, the only reason they failed on fallout 3 is i was testing them, and they are alot better than the 8.10-12s...