Need help with workgroup issue

Hey guys, I'm having this strange problem. I can't see my own computer listed in my workgroup, neither can other computers see mine listed. If they run a search for my computer's name though, it appears in the search results and is completely accessible and browsable, according to the set permissions, of course. So my question is, what could be the reason that it stays invisible or how could I make it appear automatically in the list? I'm running Windows XP SP2 , Windows firewall is disabled, running another firewall that has the local network in its trusted zone, and I tried disabling the firewall loading on boot up and rebooting, and it didn't change anything. Any help will be appreciated.

 

Does your DNS servers and WINS servers match with other pc's?

 

No, because it's a VPN. Yet I can see the other computers. And even if I disconnect from the internet, I can't see my own computer in my workgroup in My Network Places, unless I specifially run a search for it.