I have just setup an OES Linux box, and created NSS volumes. The
objects for these volumes correctly appear in NDS.

At this point on a Netware server, I would immediately be able to go to
a Windows (XP) machine with the Novell client installed (tried 4.9sp2
and 4.83 both) and map a drive to one of these volumes.

I cannot do this.

I can map a drive but it appears to be going through SAMBA, not NCP.

DO I have to "turn on" NCP for these NSS volumes somehow (they were
created with the command line nssmu command.)