Games go to the TaskBar

[Damo79]

Having a really strange problem at the mo that i hope some one can help with. I have recently splashed out on a new system,

Core 2 Duo E6600 2.4GHz
2GB Ram
Nvidia 8800GTS
Windows XP SP 2

as awsome as the machine is the problem i have is that now and again when i am playing games, (CM Dirt, Fear, even Bricks of Atlantis) the game just drops to the taskbar and there is windows in all its glory.
I click on the game and it loads up as if nothing happens. It can be a problem if you were just putting ur nice evo 8 through a hard left though.!!!!!
Any thoughts or comments would be great.

Thanks

Damo