windump on browsing of shared folders across vpn in winxp


I have a problem when i try to connect to a shared folder in the same
domain across a VPN to another machine. When i fire up windump, in
comparison to local access to a file server, the protocol that windows
select when browsing is over port 80, hence windows explorer pops up
with a blank window but no file shares to be seen.

I'm using windows xp service pack 2, is there some service such as
webdav that i have to turn on ? netbios over tcp/ip is on and computer
browser service is on. It is very strange as the outgoing port goes to
port 80. I'm testing a remote vpn client that connects to the network.