Windows ME unable to authenticate

Binary package hint: samba

I recently upgraded an Ubuntu workstation from Gutsy to Jaunty. It was acting as the printer server, and had some Samba shares exposed. A Windows ME computer on the same network had a batch file in the "Startup" folder of the Start Menu that reset the time from this workstation and mapped a share (as well as some shares from a Debian Etch workstation). The Windows ME workstation is also configured to print to a Samba-shared printer on the Ubuntu workstation. Since upgrading, the batch-file gives an error-message trying to get the time; prompts for the password on the share, and doesn't accept the user's password; and opening the printer in "Start → Printers..." brings up a password box, and the user's password is not accepted.

C:>net time \\ubuntu_server

gives the error-message

Error 5: You do not currently have access to this file. The file may be
marked read-only, or it may be part of a shared resource such as a folder, a
named pipe, a queue, or a semaphore. You can use the ATTRIB command to change
the read-only attribute, or try again later when the file may be available.

C:>net use o: \\grendel\opt

causes a password-prompt, and even after entering the correct password (`smbpasswd` and `passwd` were both used to set the same password for this user) it gives the same error-message:

The password is invalid for \\GRENDEL\OPT. For more information, contact your
network administrator.
Type the password for \\GRENDEL\OPT:*****

Error 5: You do not currently have access to this file. The file may be
marked read-only, or it may be part of a shared resource such as a folder, a
named pipe, a queue, or a semaphore. You can use the ATTRIB command to change
the read-only attribute, or try again later when the file may be available.

Browsing to the printer in "Start → Printers..." brings up a dialog with the title "Enter Network Password", message "You must supply a password to make this connection:".

This batch-file used to work fine, against Ubuntu G. "NET TIME" and "NET USE" work from Windows ME against the Debian Etch workstation I mentioned. My workaround for now is to do "NET TIME" against Debian rather than Ubuntu and not mount the "OPT" share. I'll probably either move the printer or re-export it from the Debian Etch workstation.

$ lsb_release -rd
Description: Ubuntu 9.04
$ apt-cache policy samba
samba:
  Instalados: 2:3.3.2-1ubuntu3.3
  Candidato: 2:3.3.2-1ubuntu3.3
  Tabla de versión:
 *** 2:3.3.2-1ubuntu3.3 0
        500 http://us.archive.ubuntu.com jaunty-updates/main Packages
        100 /var/lib/dpkg/status
     2:3.3.2-1ubuntu3 0
        500 http://us.archive.ubuntu.com jaunty/main Packages
     2:3.2.3-1ubuntu3.7 0
        500 http://security.ubuntu.com intrepid-security/main Packages