Error trying to backup both iPhone4 and iPad (1) after 4.3/iTunes/XCode updates After the slew of updates this week I'm no longer able to backup either my iPhone 4 or iPad.  There are two errors:

"iTunes was unable to load data class information from Sync Services. Reconnect or try again later"

and 

"iTunes could not back up the iPhone "Lee Hinde's iPhone" because the backup session failed."

Probably not coincidentally the existing backups don't show up in iTunes (preferences/devices).

My searching on these errors indicates they mostly seem to happen to Windows users and I'm on Mac 10.6.6.

Synching actually works. Odd. I.e., if I update an app on either device or the Mac, they are transferred as they should. It's the backup that's not happening.

I also updated XCode and the one similar issue I saw on Twitter was from a developer, so I'm leaning towards blaming XCode.

Did a Repair Disk Permissions.

Any tips appreciated.
I would try manually checking the backups folder(username/Library/Application Support/Mobilesync)and then deleting anything in there. That error message makes me think Xcode but you could try resetting Sync History from preferences in iSync and resetting the SyncServices folder as per http://support.apple.com/kb/ts1627 . Doing that will wipe sync settings for your iPhone so you will have to re-check the information you want to sync in iTunes. I am running Xcode 4 on 10.6.7 and I have not run into this issue. Hopefully this resolves the issue, let me know if this helps. Also as per the last suggestion I would recommend following the instruction on the apple support site for reinstalling iTunes @ http://support.apple.com/kb/ht1224