Problem: Smbpasswd allowing two users with the same SID

[Emidio Augusto Arantes Macedo]

When adding a new user using throw smbpasswd, and the  SID  to be added 
already exists in tdbsam database, an error message is displayed like that:
hostname#  "( echo 'password'; echo 'password' ) | smbpasswd -as
'newuser'"
Unable to modify TDB passwd ! Error: Record exist
Unable to modify TDB passwd ! Error: Record exists
occured while storing the RID index (RID_00004a3c)
Failed to add entry for user newuser."

But when runned the same command  the user is added with the same SID as 
one already added, without any warnings. The SID calculated by the samba 
algorithm, is based on the unix uid, but in my network uids are always 
being renewed. Does anybody had the same problem? Is there anyway to 
always block smbpasswd when adding a new user with an existing SID? Thanks!

Emidio