Well that's just the thing, there is nothing to fix on the Vista to Vista interaction. Everything there works as intended.
@eschw95458 any thoughts on the DNS issue?
If you can ping the macs from the Vista machines by name, then the DNS is working. If not, then you do have a DNS problem either creating your issue, or on top of a different issue. Appoint one device to be the DNS server and make sure that all the records are in it and that everything references it, and that it has the proper forwarders setup for outside resolution. Forget WINS unless it's actually required by something you are running as I believe that WINS isn't used by default in Vista.