Vista Tutorial - Vista Computers Don't Discover other Vista Computers

I have two new Vista Computers, both running Vista Home Premium 64 bit. I am trying to setup sharing so that I can use the same printer and share files. However, when I type in the other computers \\computername into either of the two computers search boxes it says 'Windows cannot access \\computername'. Both computers have the same Network name and have Network Discovery, File Sharing, Public Folder Sharing and Media Sharing Turned on. The Computer w/ the Printer has Printer Sharing turned on. Both Computers also have Link-Layer Topology Discovery Mapper and Responder enabled. I can't figure out why they won't recognize each other. My only guess is that my wireless router is not allowing them to see each other. I have a home network connected to a wired router that one of the computers and a Linksys wireless router are connected to. The second computer passes through the Linksys wireless router to get to my home network backbone. Any ideas?

I have taken my wireless router out from between my home's router and the PC it was connected to. I can now see the other computers in each computers full map. However when I try and access the other computer from either computer, I still get the "Windows cannot access \\computername" message.

This appears to be a Norton Utilities Firewall issue. If I configure Norton's Firewall settings to allow the ip address of the other pc, then each pc can then connect to and share resources with the other.