This happended ot us yesterday, one of us was KL1 (may have that wrong) and the ticket person in SFO couldn't give us a seat for the LAX - EWR portion. She asked another person how to get around it, and they asked the next person (lucky it wasn't busy yesterday afternoon there), and he knew the function key sequence to open it up so she could get us seats. She tapped a few keys, and poof, boarding cards.