ok - I don't really know WHERE this one goes but this looks like a good candidate.
RMXP has an issue running in Windows 7 if you have your text size set to 150%.
This is what happens if you alt+enter to run in full screen (or have your game start in full screen).
Alt+tab out and back in again fixes the problem - until you go back to a window and go to full screen again.
Any ideas on how to fix this one? Simulating a couple of Alt+tabs doesn't do the trick.