w98 cannot browse network in w2k domain

I upgraded a PDC to a w2k DC. There are two other NT BDC running in the domain. It’s running in mixed mode and the w2k DC is running active directory. Setup DNS and DHCP. The domain has a mix of w98 and w2k machines. All machines can logon to the domain now and able to browse the network. The w2k machines logon to “xyz.abcd.org” domain, no problem. The w98 machines logon to the pre w2k “xyz” domain with no problem and can see everybody else in Network Neighborhood. But when I switch the w98 machines to logon to “xyz.abcd.org” , it’ll logon and get all the drive mapping and get the right IP, but can not browse or see other computers in Network Neighborhood. Why ? How to solve this? Please help.
Thanks.