Can't see other computers in workgroup

I have been doing support for ten years or more so I am not at beginner level. I went to a new customers office yesterday. They wanted a new network set up. Just three computers. Wireless router and internet access in place but no file or printer sharing. They wanted the router and modem moved. Got everything set up and moved. Set up a new workgroup. Set the computers up with fixed ip's in the same range. Set up shares. Cannot see any of the computers from  any of the others. Can't figure it out. Computers are mixed. The two primary ones I have been working on are an xp compter with the shared resources and a Vista machine (home premium). I only have one more idea. the wirelss router is a Linksys and the wap is set up with a name of ackrtion. The workgroup is also ackrtion. I am going to try to change the name when I go by tomorrow, but if that doesn't work I have no idea what to do next. Everthing I look at seem to be ok. I have not worked with Vista very much at all so finding all of the things I am used to finding in XP is kink of difficult, but unless there are some new things we should be able to see the shared resources.