I've been having this problem since last year and finally decided to google it because I was tired of restarting the client in the middle of a game. Seems after reading this forum it's not the desktop environment, so it has to be the Teamspeak client or the windowing system.

For this is o:

OS: Debian 8 (Jessie)
Desktop: Gnome 3 Shell

Can't find any notable logs regarding the issue. Seems like it happens if the screen is allowed to lock, possibly.