Can not upgrade NMS4.15 to iMS5.0

I'm trying to upgrade form NMS 4.15 to IMS 5.0.

We're running NDS 4.12. I've followed the migration instructions, ran the ims_dssetup.pl utility, got up to installing ims. The install fails with:

"ERROR

A serious problem occurred while installing the iPlanet Messaging Server Common messaging configuration in LDAP. It reported the following problem:

The server configuration for the Common messaging configuration in LDAP cannot be created."

Here's what the log file reports:

"NOTICE: Creating Common messaging configuration in LDAP.

ERROR:

TYPE: LDAP

LOCATION: LLdapEntry::WriteToLdap

DETAILS: Unable to create entry 'cn=service, cn=configuration, cn=msg-parent, cn=iPlanet Messaging Suite, cn=Server Group (2), cn=parent.inl

ec.net, ou=inlec.net, o=NetscapeRoot' in LDAP server.

ERROR:

TYPE: Meta Data

LOCATION: LMetaDataLdap::PerformMetaDataOperation

DETAILS: Unable to create entry 'cn=service, cn=configuration, cn=msg-parent, cn=iPlanet Messaging Suite, cn=Server Group (2), cn=parent.inl

ec.net, ou=inlec.net, o=NetscapeRoot' in LDAP server.

ERROR:

TYPE: Meta Data

LOCATION: LMetaDataLdap::WriteAllData

DETAILS: Unable to create entry 'cn=service, cn=configuration, cn=msg-parent, cn=iPlanet Messaging Suite, cn=Server Group (2), cn=parent.inl

ec.net, ou=inlec.net, o=NetscapeRoot' in LDAP server.

ERROR:

TYPE: Installable

LOCATION: LMetaDataInstallable::Create