[Samba] samba windows/Unix user name problem

[mattes]

fedora 11 install with
   samba-3.3.2-0.33.fc11
   samba-3.4.2-0.42.fc11  (updated later)

I used 'system-config-samba' to setup shares and users.
Attempts to access the samba shares from windows xp (sp4)
failed.

After an afternoon of try and error I finally got access.
I was always used the windows name 'racer5' to login.
I finally got it to work when using the unix username 'xunil' instead.

Is that the intend? or a bug?
What is the windows user name used for?

here part of my setup

  cat /etc/samba/smbusers
  # Unix_name = SMB_name1 SMB_name2 ...
  root = administrator admin
  nobody = guest pcguest smbguest
  xunil = racer5


using unix test tools pretty much reveal the issue:

  smbclient -u racer5 //192.168.15.2/samba   FAILED
    session setup failed: NY_STATUS_LOGON_FAILURE

  smbclient -u xunil //192.168.15.2/samba    OK
  smbclient //192.168.15.2/samba             OK

same stands for mount

 mount -t cifs -o user=racer5 //192.168.15.15/samba /mnt/x
  all  mount error 12 = permission denied

 mount -t cifs -o user=xunil //192.168.15.15/samba /mnt/x   OK

windows xp explorer
  \\192.168.15.2\samba  user 'racer5'    FAILS
  \\192.168.15.2\samba  user 'xunil'     FAILS

in all cases the smb password is/was used!

mattes