I can understand your frustration but after being on the phone with Apple for three hours yesterday at different times they are seriously helping to define the problem. I can confirm it is NOT the ATV itself as home sharing on an new iPAD is doing the same, obviously is could be linked to home sharing itself, but I don't see how.
It appears that when I run it from a differnet device, i.e. my Mini MAC server, the problem dissapears! Its using the same version of OS, same iTunes but two things that are differnet 1. I am using a drobo external FW800 DAT on the MAC Mini and on my MAC Book Pro I am using a Promise R6 Thunderbolt drive, which interestingly I have just found out about a firmware upgrade, which I have just applied, and have started the test again. If it is that then I am confused as I have had this for over a year and changed nothing. Additionally everyone who has this problem appears to have differnet hardware.
The only other thing that is differnet is the software I have loaded, so if it does it again Apple are going to start looking at that. The problem I have appears to be the same as everyone else, BUT it could be caused by differnet reasons on differnet machines. Eitherway once we have eliminated every other option and hopefully discovered what is causing the problem I will feed back what we found.
I feel like giving up, but after spending so much time and effort in trying to resolve the issue I have gone past the point of no return.