Hi, I've got the same problem, but with a slightly different twist. I get the message "Xpc is not accessible. You might not have permission to use this network resource. Contact the administrator of this server to find out if you have access permisions."
I've tried a number of things. The thing that initiated the quest was loss of internet for one of my computers. I have four PCs on a linksys WRT54GS gateway. Three are working fine, the fourth can access the other computers as well as the gateway (192.168.1.1), but cannot find the internet for some reason. I tried installing the latest internet browser to no avail. Firewalls have been disconnected, leaving only the router firewall, which is apparently all that is needed fro a home network.
The PCs are all windows XP SP2.
I can ping any computer to any other computer and can connect from the problem computer to any other computer. But none of the other computers can connect to the problem computer, which leads me to suspect that this is related to the internet connection failure.
I've tried mapping the drive with connection to a different user, IRPStackSize, and a few other diagnostics, but haven't solved it yet. Any ideas?