I was trying to price a multi-city itinerary next spring that has an IAD-LHR in paid business and UA.com is telling me that business class is not available on that flight (it is a three-class flight that is practically wide open). But when I tried a simple IAD-LHR it was available. That kind of thing is very annoying. I sort of doubt that it is a glitch - I wonder if they are trying to force people going on to other cities to book through BRU or FRA. I wonder if I can book it on orbitz (though whether I will book it on UA metal at this point in increasingly unlikely).