Unable to see new shares on win2k

I have a p2p network with most machines running win2k, recently i created new shares on the win2k
machines and the machines running win98 can not see them at all. can not say exactly when the problem started but i know it used to work since i haveno problems with shares i created months ago. Let me also mention that about 2 months ago some of the win98 pcs were infected by NIMDA HELP!