Exchange 2010 bug not removing mailboxes after migration to an new database

While moving mailboxes from one database to another the move request finishes with a warning: Warning: Failed to clean up the source mailbox after the move. Error details: MapiExceptionUnexpectedMailboxState: Unable to delete mailbox. (hr=0x80004005, ec=2634) You will see the mailbox is disconnected but won't delete. To remove the mailbox use exchange powershell and enter these commands: $aa=Get-MailboxStatistics -Database Mailbox database name| where {$_.DisconnectReason -eq “SoftDeleted”} $aa | foreach {Remove-StoreMailbox -Database $_.database -Identity $_.mailboxguid -MailboxState SoftDeleted}