Restore a single mailbox in Exchange 2003

Environment:

Exchange 2010 SP1 With Win 2008 R2 Enterprise

Exchange 2003 With Win 2003 X64

Try Steps:

1. Currently all users’ mailbox are located in Exchange 2010,
2. Restored an old database(had been backuped from Exchange 2003) to recovery database of Exchange 2003
3. Try to extract a user’s mailbox to PST file from recover database on Exchange 2003 system by exMerge tools, it failed,