Access to Win2000 Server

I am trying to access a share (a directory) on my win2000 advanced server from my win98 machine. When I click on the server listed in network neighborhood I am confronted with a request for password. No password that I have assigned works. Works like a charm when I access the 98 machine from the server.
I am running this server as domain controller and wonder if this is the problem.
What am I doing wrong? Any ideas?

Sid