NT (w/SP3) can not access any Samba shares that require passwords

[Dave]

  I have a new workstation with NT 4.0 w/ Service Pack 3 installed that can
not log in to any of the shares that require a password. The error message
says the machine is not allowed to login. They can access any share that
does not require a username and password.
  I thought SP3 took care of this? I have several other NT 4.0 clients
w/SP3 that are working OK.
  The SAMBA server is a DEC Alpha running DEC UNIX 4.0A w/Samba 1.9.17p4. 
  What did I forget?
Dave.
dburwell at telecom.com