Apple TV drops home sharing connection wired only

Weird. For a month or so I used my ATV for iTunes stuff. I changed it to wired when I found out some ATVs had flaky WiFi cards.

Well, whenever the ATV goes to sleep, it won't pick up the home sharing network when it wakes up. Once it sees the network sharing, I can watch everything for as long as I want to watch. No buffering, no hesitation, no "An error has occurred" messages. Works great via WiFi now that I've got it changed out from the genius bar.

I've
changed out the network cable from the ATV to the switch
changed out the switch
changed out the ATV (I've got two)
changed out the network cable from the switch to the Airport Extreme.

Each time I made a change I waited a week to see what happened.

Goes to sleep, can't see the network sharing when it wakes up. Only on wired network.

Any ideas?

Thanks
DanH