When you try to move a mailbox from an earlier version of Exchange server to a Microsoft Exchange Server 2010 server, the operation fails. Additionally, you find the following events are logged on the Exchange Server 2010 server.
This problem occurs because a message in the effected mailbox misses a certain property.
To resolve this problem, install the following update rollup:
982639 Description of Update Rollup 4 for Exchange Server 2010
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.