When I play audio/video with MacBook Pro attached to Thunderbolt display the audio steadily worsens until, after about an hour, the sounds are no longer recognizable. Restarting the audio/video temporarily fixes the problem--for about an hour. Then, same thing again. I don't notice this when using the Mac without Thunderbolt. I've tried to search the Forum here for a thread but I didn't find anything. Anyone encounter this problem?