samba - Oct 2002 - assert on frag length failed when enumprinters

What is the cause of this...

rpcclient $> enumprinters
result was NT_STATUS_UNSUCCESSFUL
rpcclient $>

and I see in the log -

[root@littleboy samba]# tail -f /var/log/samba/log.lnx01688
[2002/10/21 09:00:21, 0] rpc_server/srv_pipe_hnd.c:unmarshall_rpc_header(414)
  unmarshall_rpc_header: assert on frag length failed.

but I can get info on a specific printer -

rpcclient $> getprinter cisdj
        flags:[0x800000]
        name:[\\littleboy\cisdj]
        description:[\\littleboy\cisdj,HP 2500C Series Printer,CIS Color Inkjet
Printer]
        comment:[CIS Color Inkjet Printer]

But I can't change the driver -

rpcclient $> setdriver "cisdj" "Lexmark Optra R"
SetPrinter call failed!
result was NT_STATUS_UNSUCCESSFUL

Neither of the above produce messages in the log. (debug level 10)

This is with Samba 2.2.6