[Samba] win98 browsing problem across VPN subnets

[snowch at care4pcs.info]

I have just setup a VPN connection three sites using IPCOP. 

Everything seems to be talking ok, apart from browsing the network neighborhood.  There are no NT/Win2K/XP servers running on any of the sites, all sites are just running win98 pc's using tcp/ip.  I have tried configuring all PC's to be on the same workgroup and setup sharing, but still each site can only see the pc's connected on it's that site.  

I have read in some newsgroups that I need to setup a WINS server, and others have suggested setting up a PDC server. Who is correct? 

I have an e-smith server (linux/samba/qmail/etc) that is running at one site to distribute emails, and I have the possibility of setting this server to be a (samba) domain master.  Would this resolve my browsing problem, or would I need to setup WINS browsing?  

Any help will be appreciated...

Thanks,

Chris Snow