Network Neighborhood Disappered

Running a single NT Domain with PDC, 4 BDC’s.
Approx 100 Win95 clients in one workgroup. Never had problems before, has worked for years… no changes on server side that would effect this. Can ping other systems, can do a “find” and find a computer… just can’t browse net neighborhood…get “unable to browse network” error when I try to browse on client or on server. Any ideas?