hi, english is not my first language so...

i got RAGE days ago, in order to play it without texture problems i have to update my ATI driver to 11.10 preview 2 for rage.
since then, RAGE runs fine.
here comes the problem, it doesnt work well with fallout NV anymore, the game is playable, but quite choppy
does any1 has the same problem and find a solution? please share with me. thanks alot!

my pc spec:
i7 860
ram 4g
2.5t HD
ATI 5770