I don't know if this is the right place for this question.

Have XP SP2 32 bit with new 4650 video card.

I use a 24" screen in portrait 1200 x 1920.

Works fine, but when there is heavy processor activity I get very annoying black flashes on the screen.

Especially and mainly I get them when Omnipage is OCR'ing or Google Desktop indexing with Nuance OCR plugin. This asks a lot of processor.

I OCR during the whole day. So black flashes are getting too much. I need a solution. I cannot work like this anymore it's realy getting too much.

Sometimes more seldom I get smaller resolution, taskbar below instead of above, or black sceen with stripes. Monitor on and off makes it go away. This is minor annoyance.

I changed the monitor : it stayed.

I tried DVI, HMNI and VGA : they all gave the problem.

Sometimes after 12 hours of working I get blocks of inverted colors for 5 minutes. This is minor annoyance.

I never changed anything a overclocking, underclocking. I don't play games, just office with a lot of heavy OCR.

Can somebody help me ?