Failed to cleanup the source mailbox after the move.

When migrating users from Exchange 2003 to Exchange 2010 I recieve the following warning after the move complets:

Warning: Failed to cleanup the source mailbox after the move.
Error details: MapiExceptionNotFound: Unable to delete mailbox. (hr=0x8004010f, ec=-2147221233)

It appears that my mailbox exists on both servers and in both stores.  If I delete the mailbox from the 2003 store it also deletes the mailbox from the 2010 database as they are still "linked".  How do I properly complete this migration?

Regards,

Eric