When I play a dvd in my iMac, Dvd Player randomly pauses without anyone touching the remote control. I try to press play on the remote and nothing happens. I have to manually press the space bar on the keyboard to get it playing again. This has happened for two dvds. This has never happened before. This happens repeatedly. I didn't restart it once and it automatically began playing by itself a couple minutes later. I am running Mavericks 10.9.1, Mid 2011 iMac. Any ideas on what is causing this?