Hi - sorry about the trouble! Hmm. It does sound like it's similar to one of the issues @robepriority is running into. I'd suggest trying the same things:
1) Rebooting, if you haven't recently
2) Shutting down whatever else you might have running
3) Making sure your graphics drivers are up-to-date
If you have windows aero effects turned on, actually, turning them off *may* be worth a shot, too - it might free up more system resources. See this thread for a bit more info (different issue, but same potential thing to try):
http://fractalsoftworks.com/forum/index.php?topic=19034.msg296949#msg296949Does this happen in fullscreen mode, btw? I'd also try different combinations of "windowed at less than max resolution", "fullscreen unchecked but with max resolution", and "fullscreen checked at max resolution" - all of these do something a bit different under the hood which may factor in.