I have this problem with skype and the game league of legends. Whenever i have a call in skype running at the same time as a league of legends game. Both the league of legends client and my skype call crashes.
Just the other day i was in a 2hr long call with someone and then decided to start playing league of legends. The moment champion select ended and the game started, they both crashed and i couldnt get back into my skype call or rejoining my game in LoL. This event has been only one of the many times it has happened. The LoL support team told me to find help here.