By default during installation, some versions of Red Hat Linux add an entry to /etc/ hosts as follows :
127.0.0.1 loopback "hostname"."domainname"
This causes Samba to loop back onto the loopback interface. The result is that Samba fails to communicate correctly with the world and therefore may fail to correctly negotiate who is the master browse list holder and who is the master browser.
Corrective Action: Delete the entry after the word "loopback" in the line starting 127.0.0.1.