iOS5: The iPhone ... Could not be synced because the sync session failed to start

iOS5 continues to be a problem.  One of the main complaints is an error encountered when attempting to sync an iPhone or iPod to iTunes:

"The iPhone [device name] Could not be synced because the sync session failed to start"

Several work-arounds have been suggested including simply restarting the iOS device. One procedure that seems to work well is to remove the device backups from iTunes.  Before you do this, make sure you backup your backups folder: ~/Library/Application Support/MobileSync/Backup/

• Connect your device and open iTunes
• Go to Preferences/Devices
• Delete all backups
• Click "OK"
• Restart iTunes and attempt another sync

Sometimes you may see duplicate backups listed.  I found that by deleting all but one backup also allows the device to sync.

Apple's iOS troubleshooting page has some good tips:  http://support.apple.com/kb/ts2529

"You are unable to log in to the user account [account name] at this time.

Problem:  an AD bound Mac shakes off login attempts and returns a message that says:

"You are unable to log in to the user account [account name] at this time.  Logging in to the account failed because an error occurred."

There are two things to to try:

First, update the Automounter master map as outlined in this Apple KB article:

http://support.apple.com/kb/TS3346

Secondly, if the user has a home folder path specified in their AD profile (Profile tab), remove it.

How OS X uses login names to generate Kerberos tickets

AD users have two valid names that can be used for authentication: the login name and the "pre-Windows 2000", or "short" name. 

OSX recognizes both of these as valid, however in order to have a Kerberos ticket granted the user must login with the short (pre-Windows 2000) name.  Login attempts using the long name or domain\username will not be granted a Kerberos ticket.

Shaking Log-on in OS X: The Ongoing Saga

Yet more things to check if a bound Mac refuses to allow authentication by an AD user:

Open the user's AD profile in Active Directory Users and Computers (ADUC) and click on the "Accounts" tab.  Check that both the log-on name and pre-Windows 2000 name are the same, that both are unique on your network and that the user is entering the name exactly as it appears in the profile.