Network resource access

My Network consist of a single Windows 2000 domain, there is only 1 Server running Windows 2000 Server for Small Business. We use DHCP and DNS on the Server to assign IP address to clients (Windows 2000, NT 4, 98, 95). Users report that occasionallythey cannot access network Resource (sharing by other client computer) using Windows Explorer, but the map drive are always available to use. The users sometimes use command:
ipconfig /release
ipconfig /renew
Then they could browse and access Network.

Does any one experiences the same problem? Would you please show me how to fix this problem. Thank you for your help.

quanduong@outsourcedatacenter.com
713-208-1201