[Samba] bug tdbsam

[KONFERENCE]

Hello,

I found duplicity in passdb.tdb.

I deleted duplicity user (it is machine):
#pdbedit -x -u FS4$
#pdbedit -Lv | grep fs4

I add new machine account with same SID:
#pdbedit -a -m -u FS4 -M S-1-5-21-1022826735-1298021733-666385194-2282
#pdbedit -Lv | grep fs4
Unix username:        fs4$
Logon Script:         fs4_.bat
Unix username:        fs4$
Logon Script:         fs4_.bat

...and user FS4 is twice again.
Why has user FS4 in database duplicity record?
It is bug tdbsam?
Could I repair tdb database?

If I add completly new user problem is not.
I tried restart smb service, without success.

Thank you for your help,

Honza