I tested this even more in Windows today, playing a multi player game with multiple CPU (but no network slots/players). The CPU's were fighting each other and I was an observer. When I resumed the game after a long pause, it started at normal speed, then, after a second or two, got stuck for some seconds, and then continued at high speed for some more seconds, to return back to normal speed shortly after. So there is a glitch there, this shouldn't happen in a non-network game in my opinion.