unfortunately i don't know the history of this db.

i was trying to recreate this scenario on a test server but i was unable to map/alias a user as dbo since that account exists in all of the dbs (sql 2008), so i too assume that the problem db may have been upgraded from older versions.

transferring dbo schema ownership as suggested above is also an option, and i wanted to transfer it to a 'dbo' user account as this seems to be the sql 2008 standard, but this user account is already aliased as the dbo, so i'm looking for a way to unmap it.

i'm looking at trying drop alias but don't want to risk losing the dbo schema.