"Shrinking" Browse LIST with Multple Ethernet Switches!

[Lawrence Houston]

Fellow Samba Users: 

A few months back we "upgraded" from a standard 10 Base/T & Thin based
Ethernet LAN to using multiple Cisco Ethernet Switches (Model 1900s
connected in parallel).  Since which time our Browse LIST (Network
Neighborhood) shrinks over time.  I have a SunOS 4.1.3 SPARC/10 running
Samba 1.9.17p4 configured as our Domain Master, with a variety of SunOS,
Linux and WIN95 Boxes pointing towards it as their WINS Server.  Over time
the Samba Browse LIST shrinks and will end up missing many of the machines
within our Workgroup.  Configuring the Cisco Ports to have "Static" 
Ethernet Addresses for the Machines within our Workgroup does appear to
help with Manual Searches, but does NOT prevent the Browse List from
shrinking!

Is there anything in particular I must do with Multiple Cisco 1900's
Ethernet Switches running in parallel (either with the Ethernet Switches
or with the Samba/WIN95 Configurations)?

TIA

Lawrence Houston  -  (houston at boyd.geog.mcgill.ca)