dbajunior (9/15/2011)
Went there, but there are no users listed in the 'Users or roles:' area.
from this it sounds as if the user is dbo of the database (not quite the same thins as being in the db_owner role, but it will have the same rights plus the ability to add other users to the db_owner role).
To remove this user you need to set another login as dbo of the database, use command alter authorization or exec sp_changedbowner for this.
running sp_helpuser you should see dbo mapped to the login.
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