So---- I am beyond frustrated. I have had ZERO issues with my Apple TV since I purchased it back in Jan 08. Yesterday, I updated my iTunes on my Macbook to 7.7.1. Typically I only streamed content from my macbook whereas my mac mini (via ethernet through the electric outlet) was the actual iTunes library. Since the update, my Apple TV could no longer stream content from my macbook. I would get the dreaded open port 3689 error-- which seems rather ridiculous since I do not have a firewall running nor is anything blocked. So-- thinking it was a minor problem, I went ahead and disconnected the iTunes library from the mac mini and connected to my my macbook. Further problems ensued. I would get the 3689 error or some things would sync from iTunes but not be playable due to unrecognized format (although everything has worked super well in the past. So I did most everything one could do, reset the entire network (Apple TV like my Macbook connects wirelessly through my AEBS), reinstalled iTunes, restored the Apple TV twice to factory settings, etc. I even did the rebooting of my macbook with the cmd, option p, r thing I read about (which worked once to make a couple things play). However, now basically I have an Apple TV that cant sync at all with my Macbook. Ironically, my iTunes from my Macbook connects to the tv well enough that I can play my music over the Apple TV in lieu of iTunes. Any suggestions? I went ahead and made a Genius Bar appointment for Tuesday. ****EDITED***** So hopefully this helps someone else out. So today after realizing my Apple TV was now an overpriced iTunes and You Tube viewer, I tried to do some other things that I had read in different threads, such as de-authorizing my macbook, authorizing it again, logging in and out of iTunes, blah blah-- still nothing worked. I kept getting the 3689 error and at this point I had NO music, films, photos on the Apple TV. SOOOOOO--- I figured you know screw it-- I am going to just reset back to original settings all of my network. Then, I remembered that I had downloaded the NetShare Iphone App on Friday evening so I thought hmmm-- I did make some network changes to get the app working. So I went to System Preferences > Network > and saw my "fake" created wifi network to use for the netshare app. I decided to go ahead and delete that-- and then I went back to the Apple TV to set up a new connection to my MAcbook ITunes library and POOFFFF!!!!! Everything works without a hitch.