What causes a computer's video system to display items that are no longer there?

For example, when playing Solitaire, cards that are moved sometimes display in both the old and new locations or between the card stacks. Display doesn't change until I begin a new game. I've changed video cards and have tried to get answers from the video card company tech support and tech support forums, but to no avail. Mobo is Asus P4P800 SE; video is PNY 256MB AGP; RAM is 1.5GB.