A strange situation

[Zhou Senqiang]

Hi,
   In the office I have three machines. The are connected each other.  I  installed 
the Samba 1.9.18p4  on machine B (SUN-US1-M140 
Solaris/2.5) and Samba 2.0.3 on machine A (Linux 2.2.5).  The workgroup of
A and B is same: lab.  The other client machine C is win95, which is in
different workgroup:cir.   Now the situation is that: From the client C, the
server B is visible but  A is invisible( using the explorer in win95).  On the
server A, I run the command: smbclient -NL A, the output is :
        Sharename      Type      Comment
        ---------      ----      -------
        homes          Disk      Home directory
        temp            Disk      temp       

       Server               Comment
        ---------            -------
        B                     Samba 1.9.18p4
        A                      Samba 2.0.3
                                
     Workgroup            Master
        ---------            -------
        CIR                      C
        LAB                     A

   I wonder: now the server A ,not B, is the master of the group LAb,  why
A , not B, is invisible for client C?  Followed is a paragraph of smb.conf:
  
 [global]
   workgroup = lab
   guest account = nobody
   keep alive = 30
   os level = 65
   security = user
   netbios name = A
   preferred master = yes
   local master = yes
   domain master = yes     
   
     wins support = yes