I have observed that the since the installation of the Graphic card, i see that my overall system performance is degraded, my other applications like Photoshop works slow. funnily the games all work perfectly without any issues.
I see CPU hitting around 50 whenever i launch any application and it works slow. I have clean installed Vista 32bit and tested and still the same thing. I have removed the Graphic card and used the onboard video and didnt see the issue.
Only thing I can think of is that its the fact that you're running 32 bit vista. Adding more vRAM will deduct from the amount of RAM available to your system. Adding that graphics card effectively reduces that amount of RAM you have by 512mb.