I've had this problem many times, to the point where fixing it is a normal part of setting up Samba now. Theeasiest fix i found was to log into Webmin, and browse to Servers>Samba Windows File Sharing, and clicking on the "Edit Samba Users and passwords link.
Once in there, I would click on each users link, and when the "Edit Samba User page opened I would re-typw the password which is already setup for that user, and UNcheck the "No Password Required" box. After that, a quick Samba restart would alsways do the trick. If that still didn't work, a quick reboot of the Windows PC or workstation would usually do the trick. Hope that helps! -- Lanman <[EMAIL PROTECTED]>
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