Heh, you think you've got it bad - On my old old (now deceased) laptop, matrices used to texture themselves with the 'window restore' icon
(The window restore icon, is the one you get when the window is maximized. It's between the _ and the X.)
It could indeed be some memory problem or other - Try updating your graphics card drivers, and what are your system specs?
(Btw, nice game :o)
[Insert extremely witty comment here] :: Add me to MSN if you like, but don't expect any big favours [unless you like VB6]. ... IDK!!