OMG EVERYONE! ok...try this...but 1st let me explain!! Problem MAY be with BONJOUR!!!!
I'm on PC w. Win7-64 bit and have an iPod Touch 4G
After great pains, got iOS 5 installed. However, my ipod wouldn't sync with itunes when on the Itunes summary for my ipod under BACKUP it was selected: Back up to this computer. Also, despite clicking "enable wifi sync" the wifi sync also did not work. HOWEVER, I found that my ipod completed a sync when under BACKUP it was selected: Back up to iCloud.
So, with that problem dead ended i turned to messing around with iCloud. Created my iCloud using my apple ID fine. After my first initial iCloud back up taking 4 hours or so, I completed an iCloud back up from my ipod. But last got to wondering...where are all my photo roll pics (800+) and notes etc going since i turned on photostream etc. I messaged a friend through the new messenger and he wondered to. I sign into ICLOUD.COM ok but there you only have the email, calendar, find my ipod and iWork! SOOOO he looked into it and said are you signing into iCloud control panel on your pc!? I was like WHAT???
So, i know this is long story...lol...but I'M EXCITED. I didn't know u needed that. I installed it. And despite it supposing to start after installer finished or me going into pc control panel and clicking it, it wouldn't open. So i uninstalled...rebooted...reinstalled...itunes cloed out now...and the sign in came up.
But as most of you here were getting...i got the CAN'T SIGN IN DUE TO SERVER ERRORS.
So, tried again tonight and same thing. This lead me to all your posts here. So, I tried the winsock thing. But never rebooted my computer. As I got frustrated and let my laptop sit...but plugged in my ipod to try and troubleshoot the syncing with itunes issue SOMETHING HAPPENED THAT NEVER HAPPEND BEFORE!!!
As iTunes was trying to auto open, and error square popped up. IT WAS ABOUT BONJOUR! Said it needed to be restarted in the CONTROL PANEL --> ADMINISTRATIVE TOOLS ---> SERVICES. So I went there and it said it was started but i RESTARTED IT!
LOW AND BEHOLD, MY ICLOUD SIGNS IN NOW AND my iPOD SYNCS TO ITUNES CORRECTLY!
I have no idea if this is a fix but PLEASE TRY AND POST YOUR EXPERIENCES!!!!! Mind you i also did the winsock thing too. So, others posted they tried that and it didn't fix their signing in issu!!!