That never really happens to me. The other day me and a friend from school were playing cs:s against eachother and he kept talking to me while I was in a game to find out what server I was in and it never crashed
my games just slow down, and i like that because i only leave my msn on while playing games when i'm waiting for someone. So when i notice my game slowing down i know sumone is talking to me
The worst was when playing Quake 3 because the msn box in the corner would pop up and screw me all up