Nobbi,
I had the same expiriences as you with UA. A lot of phone agents do not know how to enter the LH number into the reservation. I then at checkin insist that my boarding pass has my number on it in order for the crediting to work out w/out me having to send in the BP's. The UA system automatically then prints the gold BP's with your status on it. It is noted as LH*G on your stub and written out on the bigger part that the agents keeps at boarding.