Apple TV Cannot Connect To This Library Problem

Question

Hope someone can help... I had AppleTV and iTunes working just fine for months streaming from my PC to the AppleTV via a wireless connection.
I am able to see the AppleTV icon in iTunes and my AppleTV shows my iTunes library by name just fine... as it always did... even if I restart AppleTV and remove the apple tv connection from itunes, they always seem to be able to "find" each other requiring me to enter that 6 (or 5?) digit passcode.
So, I guess, I am saying that from at least an initial handshake between my AppleTV and my PC running iTunes, I think they talk just fine.
HOWEVER, the problem is every time I try to CLICK on my streaming library, for instance, I go to Movies -> Shared Videos, I get a constant spinning "Loading library" followed by a:
"Apple TV Cannot Connect to This Library" followed by a "Check your network configuration and connection".
So I am confused how the initial handshake can work, that they can see each other, but the loading of the library just dies?
I am running, as of today, the last software updates for both iTunes and AppleTV.
What caused it to break? My assumption is one (or both) of the following:
1.) I upgraded, at the same time, both the Apple TV and iTunes (for PC) at the same time.
2.) I upgraded my wireless router to the D-Link DIR-665.
Am I missing some ports that need to opened on the router?

Answer 1

I have the same issue, and it sounds like others may have similar. What's weird is I watched a streamed video on the 22nd with no issues with 10.5.5, iTunes 8.0.1, and AppleTV 2.1. I went to watch something on Monday night and had the same issue you did. I checked my Software Update.log and these were the only updates (changes) to my MBP since I had it working on the 22nd:
2008-10-27 17:32:45 -0400: Installed "Migration and DVD ⁄ CD Sharing Update" (1.1)
2008-10-27 17:32:51 -0400: Installed "AirPort Extreme Update 2008-004" (1.0)
2008-10-27 17:33:58 -0400: Installed "iPhoto Update" (7.1.5)
I did installed Boxee on Friday, but in troubleshooting this week I factory defaulted my AppleTV to 1.0, then did an upgrade to 2.2 and have the same issue.
I troubleshoot technology for a living, and this makes no sense to me--you can always find something that changed to cause and issue, and I can't find anything.
One more note, I did a sniffer (Wireshark) capture, and it reported malformed packets from the AppleTV to my MBP...now I accidentally deleted the capture and didn't dig further. Wireshark sometimes misrepresents normal things as issues. I will try and re-do the capture and see if I can did deeper.
Apple please fix this!