Some of the earlier Apple TV had this problem. There was a site somewhere that had serial number wildcards and if your unit matched they would take it back by appointment at the stores. I need to find this again, its been awhile, but I had an Apple TV with the same issue in my basement and I had it replaced it with a new version and it does not exhibit that issue anymore.

This is not to say that this is the only thing that could cause this issue, but it was mentioned discreetly by Apple.