flashing on the screen....

[sk8z27]

what does it mean if there is some flashing on the edges of my screen.  i'm pretty sure that it has to do with my videocard, but are my settings too high, is it overheating?  i don't want to fry my card, but sometimes i get a little flashing towards the outside borders.

thanks,
sk8z

[congo]

Artifacting can be from overheat or a card that's faulty or not running to spec.