Browsing Entire Network

I have about 20 PCs in a remote office that suddenly disappeared from the network. They are connected over a T1 with a WINS server on their subnet. I am running a W2K AD domain and these PCs are in that domain. There is not a DC on that subnet but I am not having any login issues etc. When the PCs browse the entire network, they can only see the PCs on their local subnet. They can't see anything else. (Previously they could see everything on my subnet and other subnets.)I can't see any of their PCs from my subnet. I can ping from either subnet by name and all PC and server names are resolved. I can connect to any shares on either subnet and access everything via UNC. It is just that nothing is showing up for them in the Browser list except their local subnet. My WINS replication is working and I can find their names in the WINS and DNS databases. Does anyone have any ideas that I can try to resolve this. Thanks in advance.