Problems since purchasing a Movie on Apple TV

Question

I'm aware that there have been many people with all sorts of issues since the recent ATV 3.0, 3.1 and iTunes 9.xx updates. Thankfully (and rather smugly), I've been relatively untouched by them.
Until now.
For the first time, I purchased a movie from the iTunes store via my Apple TV. The download seemed to progress at a reasonable speed and I continued to use the Apple TV as normal while the download was running in the background.
The following day I noticed that the Apple TV had 'dropped off' of iTunes' devices list. On the rare occasions that this has happened before, I simply toggle the 'Look for Apple TVs' preference on and off in iTunes and it comes back. Not this time. For the first time ever, I got the 'port 3689' message, which I thought odd.
I restarted iTunes and restarted the Apple TV and it appeared back in the source list and began to sync my purchased movie back to iTunes. Once the sync was complete, the Apple TV promptly disappeared from the devices list again, and the attempt to re-synce resulted in another 'Port' meesage. Strangely though this time the port number was different and was in the 4xxx range.
Another restart of iTunes and ATV reboot and all was well for most of the rest of the weekend. Then I went on to the iTunes store to watch some TV trailers. After watching the trailers I then wanted to watch something from my own library only to discover that 'the format could not be recognised'. A trip to the spare room revealed that once again, the Apple TV had had a bit of a falling out with iTunes and packed its bags.
Another ATV reboot and iMac reboot and all was well again. For a time....
This evening, I find that the ATV disappearing from iTunes about every 15 minutes or so whether it is doing something or not - ie. it disappears when streaming a movie or listening to music.
The only thing I can think (though strange and unlikely) is that something in 3.01 goes astray when connecting to the net (iTunes store purchases, previews) and affects the ATV's local network settings.
Any ideas?

Answer 1

Michele,
Thanks for giving me an idea to try. I may set up manual addresses and see if that helps. But that'll have to wait until I can be bothered!, Thanks.
Mr Churchill,
From your post, I suspect you are thinking along the lines of something generating interference on my wireless network.... I've not added anything or changed my configuration in any way - but there's always the neighbours I suppose.
When I first moved to my current flat, it took some time to find a good spot for the Time Capsule and select the right channel, but when I was having problems, my internet access was badly affected and network transfer speeds were ropey - this isn't the case with this problem.
I'll monitor the situation for a while and see if anything changes. I'll post back if I find anything conclusive.
Thanks again.
Message was edited by: Easybourne