Slow to access Win 98 network-workstatio

Why are win98 workstations EXTREMLY slow to access other stations? Out of 10 machines only one can click on a different workstation & view all the shared directories in a fraction of a minute. All have the same memory all are shared. All have the same Workgroup name. All are connected via a new 3com 10/100 hub. All have rj45 connections.