Exchange 2000-Mailbox Move Failed

I have a Win2000 Server/Exchange 2000 that works great. However, we cannot move mailboxes out of one of our exchange servers, get a "Mapi Call Failed-80004005-0000-00000000" error. Have done the eseutil /p, eseutil /d, and isinteg from Microsoft's instructions. Any help appreciated as we want to make new info. stores on this and other servers and want to move mailboxes around. Is the next step the exmerge or is there anything else I can do? We can move mailboxes into the store..but not out (to another store on the same server or another working exchange server). Thanks!