Using the networking components of Thunar it is possible to browse shares on some computers but not others.  In this case a virtual machine running Windows 98 Second Edition on an internal only networks is seen in the list of computers, but attempting to open (double-click) the 98se computer fails to open the list of shares.

smbtree correctly reports the shares, and smbclient is able to access the computer by it's netbios name. (e.g. smbclient -L \\pwyll98se lists the shares and so on).

Double-clicking on the icon 'PWYLL98SE' (which is the netbios name of the computer), results in 'Failed to Open "PWYLL98SE".  Failed to reteive share list from server.'

with no password (i.e. just pressing enter)
daniel@pwyll:~$ smbtree
Enter daniel's password: 
WORKGROUP
        \\PWYLL98SE                     Daniel's 98 SE VM
                \\PWYLL98SE\IPC$                Remote Inter Process Communication
                \\PWYLL98SE\MYDOC          
        \\PWYLL                         pwyll server
                \\PWYLL\psc-1200-series Hewlett-Packard psc 1200 series
                \\PWYLL\PDF             PDF
                \\PWYLL\print$          Printer Drivers
                \\PWYLL\winshare        Windows Shared Folder
                \\PWYLL\winguest        Windows Shared Folder for Guests
                \\PWYLL\IPC$            IPC Service (pwyll server)
        \\METRON                        Dickinson-Curran Windows Computer
                \\METRON\Printer                Microsoft XPS Document Writer
                \\METRON\print$                 Printer Drivers
                \\METRON\IPC$                   Remote IPC
                \\METRON\Public 

smbclient, again with no password:

daniel@pwyll:~$ smbclient -L \\pwyll98se
Enter daniel's password: 

        Sharename       Type      Comment
        ---------       ----      -------
        MYDOC           Disk      
        IPC$            IPC       Remote Inter Process Communication

        Server               Comment
        ---------            -------

        Workgroup            Master
        ---------            -------

This is using

[global]
	name resolve order = bcast host lmhosts wins
	lm announce = Yes
	preferred master = Yes
	dns proxy = No

in smb.conf

gigolo also fails to see the shares 

mount -t cifs also fails to find the 98 computer.

It may be related to cefault of lanman security not allowed (which is what I want to be the case, I have installed active directory services client, but I guess that only gives my ntlmv2 outgoing not incoming)