Move back Mailbox from Exchange 2013 to Exchange 2007

Hi,

I have a problem with a coexistence scenario with Exchange 2013 SP1 CU 6 and Exchange 2007.

I have migrated some mailbox to Exchange 2013 but i want to migrate back some mailbox.

I have use New-MoveResquest command to do this but the move failed with the status "FailedOther" and with PercentComplete "95"%

When i try the commandlet Get-MoveRequestStatistics "Name of the Mailbox" -IncludeReport | FL Report , i have this error message (I translate the message because it's in French originaly):

15/10/2014 16:55:30 [Mailbox] Fatal error UpdateMovedMailboxPermanentException has occurred
15/10/2014 16:55:30 [aaelyw96-vm] Offline Mailbox move was postponed , transient error.

Do you know what i can do for this error?

Thanks in advance.

Sebastien