This MAV thing is getting me down a bit - I really need XP to test the game on to find out why Grey Alien and others can't even get it to run in non-compat. mode.
I have XP and that's never happened to me - and don't let it get you down. You have the basis of something very promising so just work through your code methodically and find the bug.
Windows XP Home Edition SP2, Pentium 4, 3.2Ghz Radeon 9800 Pro 128Mb 1024Mb RAM.