my three-year-old GPU has started shoiwng artifacts on teh desktop. colored blocks, stretched polygons, flickering lines across teh screen:

It doesnt crash right away, but its getting more frequent... i updated the driver yesterday and nothing changed. Is this the beginning of teh end for the card, or is there something i can fix?? Im trying to stay calm, but the card isnt cheap to replace. If theres a way to narrow down whether its the card or smth else, Id like to try it first.