Connecting to Samba 2.2.5 shares fails using \\servername

[Rob Main]

I have a Samba server (v2.2.5) installed and configured on Solaris 8. 
Each of my organization's PCs have an lmhosts and hosts files configured 
to include an entry for "192.168.1.100 servername".  The same Active 
Directory group policies apply to each node on the network.  Some 
clients can access the share successfully using the UNC path 
"\\servername" and others can't.  The PCs that cannot access the Samba
shares using "\\servername" *are* able to access the share using the IP
address only.  Pasted below is the output from "nbtstat -t" on a PC that
cannot access the share via "\\servername":

C:\>nbtstat -c

Local Area Connection:
Node IpAddress: [192.168.1.200] Scope Id: []

                 NetBIOS Remote Cache Name Table

       Name              Type       Host Address    Life [sec]
   ------------------------------------------------------------
   SERVERNAME         <20>  UNIQUE          192.168.1.100        580

C:\>

I cleared out the NetBIOS cache and re-attempted to access the 
"\\servername" Samba share without success.  I can, however, access the
Samba shares using an alias (i.e. - \\serveralias) and get to other 
Samba shares residing on different servers.  Has anyone seen this before?

-Rob