windows sp2 and nvidia mx 400-se issue

Hi, hope you can help, I've been working thorugh this for days...

I have an nvidia mx 440-se graphics card, and after win sp2 upgrade I get all sorts of issues with screen locks, mouse track residuals across the screen, pc dying etc...prior to that have had no issue with the card.

So, I reformatted, reloaded everything and all was well until I installed windows sp2, then same issue again. I reinstalled the original nvidia driver set, reduced hardware acceleration and disenabled write combining in control panel display option, also, reduced screen resolution and colour quality to take load off graphics card. Last night everything was fine, this morning, pc is back to it's old tricks, with screen freezes etc. Personal crisis time...

Can't help think that it's a compatability issue with sp2 and nvidia, and there seems to be mention of this all over the net, hoping someone has a failsafe trick to help me get through this.

Thanks.