samba - May 2010 - Solved: Error joining domain "The specified account already exists"

> I have reinstalled samba from scratch and copied my previous smb.conf.
> My main desktop was logged on in the domain. When I try re-add my main
> desktop to the domain I get:
>
> ?"The following error occurred attempting to join the domain
> "MYDOMAIN": The specified account already exists"
>
> I ?tried completely removing and re-installing samba which didn't work
> either. Removing and readding the WINDOWS7$ useraccount also didn't
> work. Thanks in advance for your help.
Reinstalling Samba in Debian changed the database to tdbsam while my
original smb.conf didn't use tdbsam. Adding the following lines to
smb.conf fixed the problem:

encrypt passwords = true
passdb backend = tdbsam
obey pam restrictions = yes
unix password sync = yes
passwd program = /usr/bin/passwd %u