samba - Apr 2009 - problems using smbpasswd to enable/disable workstations trusted accounts

Greetings,

My name is Alceu and I was trying to create some scripts to
enable/disable users when I found this strange behavior with the account
flags:

# please assume that the Unix user is already created

root@midgard:~# smbpasswd -a -m lab16$
Added user lab16$.

root@midgard:~# pdbedit -Lv lab16$
Unix username:        lab16$
NT username:
Account Flags:        [W          ]
...

root@midgard:~# smbpasswd -d lab16$
Disabled user lab16$.

root@midgard:~# pdbedit -Lv lab16$
Unix username:        lab16$
NT username:
Account Flags:        [DU         ]
...

root@midgard:~# smbpasswd -e lab16$
Enabled user lab16$.

root@midgard:~# pdbedit -Lv lab16$
Unix username:        lab16$
NT username:
Account Flags:        [U          ]
...

Looks like my workstation trusted account is now a new user in the
system. I never had experienced that, I thought that smbpasswd -e or -d
keys  would only add or remove the D flag. With pbedit works fine, but I
need to check if there are other flags that I should maintain (and I
would create a possible race condition in my script):

root@midgard:~# smbpasswd -x lab16$
Deleted user lab16$.

root@midgard:~# smbpasswd -a -m lab16$
Added user lab16$.
root@midgard:~# pdbedit -Lv lab16$
Unix username:        lab16$
NT username:
Account Flags:        [W          ]
...

root@midgard:~# pdbedit -c '[D]' lab16$
Unix username:        lab16$
NT username:
Account Flags:        [DW         ]

Is this a bug? Or there is any possibility that I'm doing something wrong?

I tested this against two machines: one with Debian 4 (Samba 3.0.20b-1)
and Kubuntu 8.04 (Samba 3.0.28a-1ubuntu4.7). Kubuntu box is fully
updated. Both are using tdbsam as backend.

Thanks,
Alceu