I recently purchased a Thunderbolt Display and it's connected to my 2011 MBP. Everything is fine and the display is beautiful. However, I've noticed a "tick" or light popping sound that happens maybe very 30-60 seconds. It can only be heard if it's quiet in the room. The sound seems to be coming from the top right (above the ports area). Is this normal for these things, or do I have a faulty monitor? I've had the monitor for a week now. At first I thought it may simply be the materials settling or something. Thanks in advance.