ghost computers on network

Hello
I am helping a friend with his small company office network.
I have not used Vista at all but am strong user of Xp
The are behind a Netgear firewall FR114p firewall and have 3 Vista 64,
pc1. pc2 and pc3. pc2 has a usb printer(usb5) that is shared with pc1.
When adding the printer to pc3 the network map shows pc1 and pc2.
then printer is added, but the test page does not print.
All computers were setup with standard vista network options selected
All use dhcp. all three support iv6p.
pc1 network name is network4 and show access to local and internet
pc2 network name is network6 and show access to local and internet
pc3 network name is work and shows access just to internet

pc1 and pc2netwok maps show the following
computers: pc1, pc2 , pc3, pc1-oc and pc2-oc. pc3 map just shows pc1,
pc2 and pc3.

When i looked up pc1 printer setup it showed the printers location as
\\pc-oc\usb5 (xps). This computer (pc2-oc) is not real.

What are these ghost computers? Are they a local iv6p private network?
How do I get any info about them? Clicking on the i just shows the attached printers.
I do not have access to the network right now so i can not answer detail questions. Sorry i know bad form.http://www.vistax64.com/images/smilies/sad.gif....
I would like to get pointed in the right direction to research this issue.

Thanks

Are these machines getting assigned static IP addresses? If so make sure that none of them are interfering with each other.

Please check the IP of the printer, if thats possible. It is double check that it is on your network with the correct IP.

I think that should work. Basically if all the IP's are correct all the machines will talk. Are you using a switch? or a router only?