Weird problem w/ user authentication

[John Twyman]

Dear all,

Have managed to put myself in a small bind with regards to user 
authentication in Samba.

Somehow (don't ask...I have NO idea), I've managed to create the situation 
where my Samba server denies authentication of one single user. Every other 
user has continued access as before, no difficulties whatsoever.

When trying to login with this one user id, Windows 98 SE replies that "the 
domain password you supplied is incorrect or access to your logon server 
has been denied".

The setup is a Solaris 2.6 box running Samba 2.0.6 with Win98 & Win98/SE 
clients.
This problem is localised to the one user id, not to any specific desktop 
machine.

It is possible to use smbclient on the unix box itself to connect to samba 
shares, but (as described above) not from a Win98 desktop machine.

Does anyone have any ideas as to what this might be? Or where I might start 
looking for a solution?

User authentication is done with unencrypted passwords and samba 
interrogates /etc/passwd (ie. I haven't set up smbpasswd, etc).

Regards,
John