Timer kept going for Opponent and Didn't Show me his Move

Happened to me twice tonight where my opponent's timer kept running but he had actually moved and it didn't show me his move. Right when I was bout to mate too against a higher rated opponent. Is that just a glitch or can some people mess with the software? Happen to anyone else? Think it's because I changed background?

You can't post in the forums yet. Play some games!