Win2k/XP Networking problem

OK, My uncle's office is almost fully networked.

I have 4 computers:

1 Win2k SP4 laptop and 3 WinXP Desktops. Now, out of the 4, 2 of the XP desktops and the 2k laptop get along fine. But one of the XP desktops won't get along with the 2k laptop. They can both use all the other computers, and the other computers can use both of their shared assets, but the 2 of them just don't work together. For that WinXP desktop, I had to install the NetBEUI and NetBIOS compatable protocols on all the computers to get them to interact with it, and all but the Win2k laptop do.

Is it possible that one of those 2 protocols doesn't work from win2k to xp and that I need to upgrade the laptop to xp?

Edit: I tried everything I could find on the net, set Node Type to Hybrid on both, made sure all the usual services were running on both (workstation, server, etc.) and also made sure routing and remote access were off on both.

make sure in folder options you turn off simple file sharing. and since its a workgroup what I do is have the same username on all the workstations so I wont get challenged for my credentials each time I try to connect to a network resource.