I've just been trying to book a reward flight having checked the ANA tool first. Despite the fact the tool shows availability, the bmi agent said there wasn't any, in any class. Do I take their word for it? Can I check with the relevant airline?

The flight was on Austrian, from LED to LHR via VIE on 1 June 2007, in business. Any ideas?

TIA

The fact that an itinerary is available on the ANA site is not in itself conclusive as availability can vary from programme to programme. For the same reason, phoning the operating airline directly is not helpful either, as reservation agents will more often than not have no clue as to what has been made available to DC.
What you could do, though, is try to build the itinerary segment by segment (LED-VIE and VIE-LHR) to check availability on each segment, as this sometimes work even where the system tells the DC agent that there is no through availability.

The box above the little circle has to be a darker beige in colour. A lighter colour shows that it's available but probably at a premium level and not the 'usual' award inventories.

I have had this on my one and only (so far) DC reward booking. I was trying to book DEN-FRA-LHR on Lufthansa and the agent couldn't see availability - eventually managed to pursuade her to look at DEN-FRA and FRA-LHR and she found it

Boo

Are you sure?

I take the lighter box to mean that the trip is available but not in the same class throughout ....

Agreed.

Also, that might be why the call centre agents insist it's not available - I've got a feeling that if their system can't do the route all in the class you want, it just says it's not available. I had this trying to book WLG-AKL-LHR in business, where the first flight is economy only.

NickB's suggestion of building the route up segment by segment is the way to go.

ANA award availability is an indicator of what is available, but it is ANA's inventory. Not all the Star Alliance programs will have the same inventory depending on the airline you are trying to fly. I frequently find availability for a United flight award on the ANA site that is not available as a UA award. United allocates different programs a set number of seats and UA can already have used up their space allocation while ANA still has seats. ANA will show availability, but UA won't have any availability for Mileage Plus members.

This is how it has been with UA. It has happened several times when I have used ANA to search for availability using UA miles. Perhaps ANA has Austrian seats, but BD does not have any seats for awards left.

No I reckon it's only UA which blocks the other *A member's award inventory. This will be a case of showing unable because the connecting flight doesn't have that class.