I have had this problem with every Vista/7 machine I've connected to this network--none can see my primary domain controller running Windows Server 2003 R2 Standard. I have several other Win 2k3 servers (some R2, some not) that are not domain controllers and my Vista/7 machines have no trouble pinging them, accessing file shares, etc. It's only the domain controller I can't connect to.
I've tried researching and troubleshooting this problem multiple times since 2006 with no successful resolution, but I'm hoping this time around may be different. I'm sure upgrading to Server 2008 would solve the problem, but that's not an option at the moment.
Because of this connection issue, I can't join these newer machines to the domain, connect them to the exchange server, certain network printers, etc.
Any creative solutions and configuration suggestions are welcome on both the Client side and the Server side. I really must get this fixed!