It is just me, or does anyone else have the situation where hitting the left mouse button to fire instead triggers the same "start" function that hitting the Windows key does? It ends up backgrounding the game until I can alt-Tab back into the game. And since it's the fire button that does it, it's always at a very critical time.
It could be just me, but I wanted to ask if anyone else has had it happen. It's really, really irritating, and gotten me killed on several occasions.