During an Exchange 2003 to Exchange 2010 migration I ran into an issue where the mailbox could not be moved to Exchange 2010 because of an “Insufficient Access Rights” error:
[PS] C:\Windows\system32>get-mailbox -Identity “Joe Sixpack” | New-MoveRequest -TargetDatabase dB01 -BadItemLimit:25 -AcceptLargeDataLoss:$true