Firewall blocks windows 7 to xp

I have a peer-to-peer network with 3 XP(SP3) machines and 3 windows 7 machines.  We were having trouble with the internet connection cutting in and out and Verizon tested and sent us a new router.  After connecting up the router we were unable to communicate between the xp and windows 7 machines.  I think I clicked the wrong thing when Norton asked me about the new network. 

 

With the Norton firewall enabled I cant see from the windows 7 macines to the "server" but I can see to the other xp machines.  When I disable the firewall I can see the server but have no firewall.  Windows Firewall is disabled in both cases.  Please advise.

 

David