Background: Single Domain with 6 Post Offices. GW802HP2 Domain and Post Offices

The Mobility server is currently serving users from three post offices. I can add users from my other three POs with no problem. When I try to add a new user from a fourth post office I get the errors in log files.

No such user found by that name (????????) in user cache
Problem syncing folder for user cn=???????,ou=student,o=tmc: exceptions must be classes or instances, not NoneType.
...[configureUser] Failed to fund user ???????? in cache or failed GroupWise Login? Can not complete this user configurations without logging in.
....KeyError: u'?????????'

The Data Synchronizer GroupWise Connector Monitor screen only shows three POs. It doesn't show any connection to the forth PO.

I've checked that SOAP is enabled on this fourth PO
SOAP threads show 5 open on this fourth PO
I can telnet to the POA on port 7191 from the Mobility server
All the redirection links displayed correctly in the fourth POA
seeing no errors on the POA
Rebuilt the PO db.

Still nothing works.

Is it possible that I need to re-create the trusted key application for the Data Synchronizer? This is the only thing I can think of at this time.