I have a similiar issue. I have an Win2000 and an XP computer in a home network. Connection hardware is my Blitzz router/wireless-access. The WIN2000 is wireless. SOftware is with Microsoft Workgroup.
I created the same workgroup on both computers. I made a shared documents folder on the XP machine. The WIN2000 machine was able to access the shared documents folder and the XP's printer for 5 months. Several weeks ago connectivity stopped.
Both machines can still get to the internet. The XP can see the WIN2000, and can browse its shared objects.
The WIN2000 machine cannot see the XP machine. The previously working icon for the shared document folder returns "... path was not found". When browsing network places, the workgroup only shows the local machine (WIN2000).
My firewall programs were configured to trust the local net and/or allow the router's range of IP addresses. BUT I have also disabled both the McAfee firewall and the XP firewall. NO help.
I have double checked the workgroup names, and the file and printer sharing settings.
I suspect this began after an automatic Windows or McAfee update, but am not certian of the exact day the problem started.
I have spent hours on this. Any help would be greatly appreciated.