Change mailbox owner to an other user in a differend trused domain

Hi

We try to change the mailbox owner on our Exchange 2003 to a user in an other trusted domain.

1. We delete the mailbox of the existing user
2. run the exchange cleanup agent
3. then go on the mailbox and select reconnect
4. choose the user in the trusted domain (two-way trust)

then we get the following error message
"Exchange System Manager"
You don't have the rights required to complete the operation
ID no: c1030728


If we change the user within the same domain it works.

also to mention is that the trust is fully functional.

any ideas how to solve this problem?

thanks a lot