I had a single itunes server running with two ATVs connected (wirelessly, wired, streamed and synced). No matter how I did it, they would either totally lose network connection anywhere from minutes to days, and then would need a reboot. Other times the main menu software would crash and reboot itself making watching anything impossible to do. I then noticed that after I lent an ATV to a friend, the stability of the remaining unit went back to 'expected cool' levels. It's now been running for weeks without being restarted. As an idea, I set up an identical itunes on a different pc and added the other ATV to it. Stability there ended up being awesome, too. Curious as to if I was on to something, I re-added both ATVs to the same itunes and almost instantly the errors returned. I tried switching the itunes server and recieved the same problems. Splitting the ATVs back to their individual sources resumed awesome stability. Next time an Apple Store employee tells me that ATVs and iTunes can support multiple libraries/devices, I'm going to call shenanigans on them and demand to see their own home setups.