[Samba] Modifying unix username with pdbedit

[Gaiseric Vandal]

I am migrating from an NT4 PDC to Samba 3.025a.  I used the "net rpc
vampire" command to transfer the user and machine accounts.  Almost all
accounts have a lower case Unix user name, except for the administator
account. Unix is case sensitive, Windows doesn't seem to care.  

# pdbedit -v administrator
Unix username:        Administrator
NT username:          Administrator

I was unable to login on Windows.  I was unable to change the "Unix
username" field with pdbedit (maybe not even possible?) so I change it under
unix.  I would have rather changed it under Windows to avoid possible
problems under unix later if someone forgets that one account is is not all
lower-case.

I am using tdbsam as the samba backend. 

How can I change the "Unix username" or other fields not explicitly covered
in the man page?

Thabks