virtualbox.org

Host system: Ubuntu 9.04 (Jaunty) on Core2 Duo T5600, 2GB RAM, nVidia 7400go with 64MB VRAM
Guest system: Windows XP, guest additions installed including 3D support
Machine settings: 768MB RAM, 8.0GB hard disk space, 64MB video RAM, PulseAudio/AC97

The problem:
I want to run Game Maker (http://yoyogames.com), which is about what it sounds like, a program for making games. The editor works great, but when it comes time to run the game, the graphics are "shifted" upward by about half a screen-height, leaving the bottom part of the screen black. The mouse is not affected, so e.g. a button that appears to be in the middle of the screen can be clicked by putting the mouse near the bottom (where the button is supposed to be).

If I set the game to run in fullscreen mode, it works fine. This only occurs when the game is set to run in windowed mode.

Here's a screenshot of the problem I'm having. The entire background should be gray, with red dots bouncing around. The executable is too big to attach, but I've posted it at http://tinyboss.net/image/balls.exe.