samba - Apr 2002 - nmbd -HUP strangeness - UNKNOWN master browser on UNICAST_SUBNET

When I do a nmbd -HUP to dump the namelist, I see the following in my
log.nmbd file:

dump workgroup on subnet  UNICAST_SUBNET: netmask=     127.0.0.1:
    RIDLEY(1) current master browser = UNKNOWN

Is this normal behaviour? I know some other people have encountered the
same problem, but I can't seem to find an answer in the mailing list
archives. (It lists the correct master browser for other subnets).

Any feedback is greatly appreciated.

Thanks
Glen Gibb