Samba PDC "disappears" from Network Neighbourhood

[gerry]

Occasionally, I cannot see the Samba PDC from a Windows client for quite
some time, say 30 min. I can still log in and my login script executes,
but in Network Neighbourhood, there is no Samba PDC. This is
problematic, because everyone's work files are now on the PDC, and while
some of their folders are mapped to a drive at logon, not all are.

Using Samba 2.0.6 on SuSE 6.1, Win 95/98 clients, PDC is a WINS server,
all clients using PDC as WINS server.

TIA,
Gerry