AppleTV connected to Mac Pro by 802.11n, G5 on Ethernet can't see AppleTV

Question

I hope someone can answer this one... In my house, I have an Apple Airport Extreme base station set up and broadcasting an open 802.11n (b and g compatible) wireless network. Connected to that network is my Mac Pro, which can see my AppleTV, and is set as its main source. Just to be clear, the AppleTV is connecting to the Airport Extreme base station, and NOT directly to my Mac Pro, by some kind of ad-hoc network.
My wife has a Power Mac G5, which is connected to the same Airport Extreme base station, via Ethernet, and it cannot see the AppleTV. I have iTunes 7.1.1 and Quicktime 7.1.5 installed, and I have iTunes set to search for AppleTV units, but no Apple TV is ever displayed by her iTunes.
I have the firewall on the PowerMac shut off, and have even tried messing with the Ethernet connection speed settings in Network System Prefs.
Has anybody else experienced anything like this? Does anybody have any good advice on how to fix it? I have done everything short of reset my AppleTV and Airport Extreme, and I really don't want to have to do that, then set my network back up.
Thanx!
Mac Pro   Mac OS X (10.4.9)   Several other Macs, iPods, AppleTV
Mac Pro   Mac OS X (10.4.9)   Several other Macs, iPods, AppleTV

Answer 1

So, you're saying that the AppleTV will only ever appear in the list of available AppleTV devices on the initial host copy of iTunes?!Yes, once the "host" is selected. However, according to another poster, it should appear in the list of all LAN connected platforms when you initiate the "Connect to New Itunes" action and then disappear from non-selected iTunes lists once a selection is made.
If so, how do you add additional sources.Normally as explained previously. However, this assumes your wife's connection to the LAN was properly made. Can, for instance, the TV device see her computer as a "streaming" source?
I go through the 'Connect to New iTunes' option, and the authentication number appears on my TV screen, but nothing ever indicates that my wife's Power Mac has recognized the AppleTV, or vice versa.If the device doesn't show up in her iTunes at this point, I would likely try turning off the Airport card in your Mac Pro and see if this makes a difference. (I assume here that when you say the TV is connected to your mac Pro via the Airport Extreme, you mean wirelessly and not via an ether connection between extreme and TV since anything plugged into the TV ether connector would override any wireless connection attempts. (As a double check, you can look at your Settings > Network page on the TV.) Since I only have one computer/TV combination and it is such a pain switching back and forth between wired and wireless connections, I just leave mine connected by a Cat 6 cable I already had. Basically, everyone on your LAN needs to connect wirelessly or everyone nees to connect wired since you can't mix connections to the TV. In any case, if you cannot see/connect her computer with TV when yours is "disconnected," then would concentrate efforts here as it would appear she has a network problem.