[Samba] Users/Machines Unable to Logon to Samba PDC

[Support]

I have Samba 2.2.7 running on RedHat Linux 7.3 (kernel 2.4.18)...  the system has been running just fine since the initial install four plus months ago.  All of a sudden, starting this mid-morning, users are unable to logon to their Windows 2000 machines.  They receive the following message:

"The system cannot log you on to this domain because the system's computer account in its primary domain is missing or the password on that account is incorrect."

These same users were able to logon just fine yesterday...  and some were able to logon just fine this morning...  but now nobody can logon.

Thinking that the computer account had gone bad for some reason, I changed the workstation from being a member of a domain to a member of a workgroup, then I deleted the account from Samba (using "smbpasswd -x computer$"), then from Linux (using "userdel computer$").  I then had the computer join the domain, and was welcomed to the domain.  After reboot, the same error message.

If I logon locally to the computer, I am able to map drives (using "net use x: \\server\share /user:username password).  I am also able to perform a "net use" on the server.

What can I do and/or test to further determine what the problem is?