Diver -- I've had this problem running Myst on my Win 7 64 bit system -- it happens whenever there's a video sequence and sometimes during animations as well. I've seen on other forums that sometimes trying compatibility mode or running the game as an administrator helps.
Would you like this thread copied over to the Glitches forum? They may be better able to help you there.
Last edited by Becky; 05/16/12 11:18 AM.