Had an interesting computer glitch... Flew on CO1673 to Denver. Checked in online to my return flight CO442 to Houston. Didn't have a printer, no big deal, I was going to be in plenty of time at airport, so headed off without a hardcopy.

Get to DEN, told it was not a CO flight but really UA442, so go to United counter. Ok (a surprisingly long walk, actually, but at least in same terminal).

Swipe my card, machine says: your UA record locator is 123456, unable to print boarding pass, contact UA agent. Hm.. UA Agent says it is a CO flight, please go back to CO. Ok (walk back seemed longer).

Swipe my card for luck. Nope. Contact senior CO agent on duty. Lots of discussion. She phones UA Global Services and they (eventually) do something to the record so that, a pass can be printed, but only back at UA. (Really long walk back this time). The CO Agent was very nice. Walked down with me. Said this had been happening since Aug 1st. She had me meet the senior UA agent, explained the situation. They typed some more stuff into the computer and yippee. Boarding pass (even got my complimentary upgrade).

Took well over an hour. Good job I was early....

Apparently what happened was that coincidentally the flight had a code share of CO442 and UA442 (i.e. same number). Computer decided this wasn't supposed to happen and so during some kind of end-of-month consolidation, it blocked all of the CO442 accounts from printing.

Morale of the story?? - for the next few months, use the hotel printer, dont rely on the ones in the airport.