hmmm, I didn't think this was a public post? But I'm happy your trying to help. Thank you.
Getting AppleTV1 to show up in iTunes has allways been inconsistant. Usually, a reboot of itunes and the mac would fix it. Toggling libraries etc.
AppleTV does not show up in Preferences.
I have not been able to connect to my AppleTV via iTunes Devices for some time now. I'm thinking since updating to Lion.
FYI. AirFoil does see it.
I can stream iTunes to AppleTV1 Speakers.
AppleTV1 Latest Software
OSX Lion 10.7.3
MacBookPro 17-inch, Late 2011
Navigate to Settings > Computers > Your Library on the Apple TV, you may be told you will lose all synced content, but you can sync it back afterwards, you won't lose any purchased content that has yet to be transferred. Then select Settings > Computers > Connect To iTunes, note the passcode that appears on screen, click on the device in iTunes and enter the passcode when prompted.
Intermittent problems are often a result of interference. Interference can be caused by other networks in the neighbourhood or from household electrical items.
You can download and install iStumbler (NetStumbler for windows users) to help you see which channels are used by neighbouring networks so that you can avoid them, but iStumbler will not see household items.
Refer to your router manual for instructions on changing your wifi channel or adjusting your multicast rate.
There are other types of problems that can affect networks, but this is by far the most common, hence worth mentioning first. Networks that have inherent issues can be seen to work differently with different versions of the same software. You might also try moving the Apple TV away from other electrical equipment.
Thanks. Networking wasn't the issue. Deleting iTunes library on AppleTV and Re-Adding it solved the problem.
I do have iStumnler. Great program!
There should be a better way to re-add or reconnect your library. Rather than having to delete all your media on the AppleTV and then re-sync. I prefer the AppleTV local HardDrive rather than streaming. Because streaming does cause network bandwidth issues.
My issue was not intermittant though. Once I lose a "connection" or rather, a synced library, the only way to add it back is to do as you suggested. When this happens, iTunes does not see it in devices. But does see it in speakers. So does AirFoil and MOG. So the network is ok. My AppleTV is also connected via Ethernet. Connecting my laptop via ethernet did not make it show up either.
I have this same problem at my office with the office ATV1. At the office, the main iTunes Library is on a Mac Mini OSX Server, connected via the LAN. Everything is LAN at the office. Same problem arrises.