Submitting a certificate request - No mapping between account names and security IDs

Hi,

I'm attempting to enable LDAP authentication for a Business Objects installation to a Windows AD DC in another trusted forest, that doesn't trust our forest.  They've opened firewalls for the server and have given me the CA certificate to add to a certificate store.

I've created a certificate request on a windows server, using Mozilla NSS tools certuil .  A new process for me, but it seems to have worked correctly.

I then sent the request to the remote forest AD admin and he is meant to submit the request and create the cert.  He got this error - I've included the relevant lines.

Request Mode:newreq - NewRequest
Result:No mapping between account names and sercurity IDs was done. 0x80070534 (WIN32: 1332)

He's submitting on a 2003 CA server. 

Any suggestions would be appreciated.

Thanks,

Sam