strange login errors

[Edwin Shin]

i hope this is to the right list. i have samba set up as a domain member
with security=domain, not as a pdc (first step toward replacing our pdc
=)). i'm not currently subscribed to the list so please cc: me with any
responses.

i have the odd situation where i can access samba shares but others
cannot and as far as i can tell, it's not related to ip restriction
(hosts allow/deny) or "valid user" restrictions.

i set debug level = 100 to try and diagnose, but i'm not sure what to
make of the output. the relevant bit from one of the client machine
logs:

rpc_client/cli_netlogon.c:cli_net_sam_logon(392) cli_net_sam_logon:
NT_STATUS_INVALID_WORKSTATION
[1999/10/06 13:05:29, 0] smbd/password.c:domain_client_validate(1369)
domain_client_validate: unable to validate password for user dummy in
domain TEST to Domain controller PDC. Error was
NT_STATUS_INVALID_WORKSTATION.

when i try the following:
    $ ./smbclient //SAMBA_SERVER/share -Udummy
and enter in the password for user dummy, i get:

session setup failed: ERRSRV - ERRbadpw (Bad password - name/password
pair in a Tree Connect or Session Setup are invalid.)

however, when i attempt connecting to the samba server as myself, it
works like a charm. this seems like some silly newbie permissions
problem, but i can't figure out where there might be a permissions
problem here since i've now commented out any hosts allow/valid user
lines in smb.conf. the INVALID_WORKSTATION error seems like a red
herring since i can log in from any given workstation if i log in as
myself.

FYI:
i'm running samba 2.05a on solaris 2.7 for x86. the samba server is a
member of an NT domain with a vanilla microsoft NT PDC. i have
security=domain set.
user dummy has a unix account on the samba server and an entry in
smbpasswd. 

thanks!

-eddie