Not to mention that anti-virus software may pop up a scheduled scan/database update window, or some other application you're using may choose to let you know it downloaded some minor update - and crash the game in the process. Plus the accidental WIN-key/multimedia keyboard presses. Oh and if you've got some instant messenger like MSN, ICQ and such running in background it's a pain as well.

Simply put, alt-tab crashing needs to go.