Samba/Winbind problem

Hey all,

I've been running a samba-PDC for about 12 months now without problems.
The PDC is running 2.2.8a, and does authentication for WinXP and other
samba boxes that are also running 2.2.8a without any problems. However I
have recently tried putting Kubuntu onto a box (called GROMIT), which runs
samba 3.0.10-Ubuntu, and I can't seem to get it talk to the PDC for
authentication. Running wbinfo with the usual switches always fails, and
GROMIT's log on the PDC says:

api_pipe_bind_req: unknown auth type 44 requested.

every time I try to get any info from the PDC. I really don't want to have
to upgrade the PDC to version 3, since that would mean doing all the other
machines too. Does anyone have any ideas how to fix this error, or any
more information on exactly what it means? I found one reference to the
same problem from a google search, but no solution.

Thanks in advance,

dave.