laggy scrolling in vista

I recently installed vista on my 4600+ dualcore with 2 gigs of ram and a geforce 6800GT gfxcard

now I installed the latest drivers for my graphicscard but I still find some things very slow.
For example when scrolling a webpage in firefox it really lags behind a lot, same when trying to resize a window. I tried disabling aero and just running the classic windows theme and that made the scolling in the browser much faster but resizing windows was still slow, even slower than before infact.

I've installed all the latest drivers for my motherboard that i could find, but still no luck.
it seems to be a very common problem:
here's is a video someone else made with the same problem:
YouTube - Vista Aero Glass Slow Scrolling Nvidia AGP Part 2

and doing a google search results in countless people with the same problem, i've read through them but so far couldnt find any solution:

laggy scrolling vista - Google Search

thanks