Slow Loading over network only specific sets

This is a good one, We have a file server and 4 Licenced stations,the file server running win98, 2 units running a4v6 on win98 one on win 95 and the last running XP with a4v7.we run tcp/ip for internet sharing. most files open ok but one is a customer analasis set with 7 databases, 5 indexes and apx 2100 records. it takes forever to load on all but the XP machine.the XP only shows one licence user as the .net file is on its harddrive and not the server. At one time the win 95 machine loaded the file very fast but now it doesn't. the net itself is a 100mps and all other programs run extreamly quick. Could this be a problem with the a4net file? when checked the network shows as net bios, shared.