KVS is pulling inventory from the All Nippon Airways website. That shows you what Star Alliance member airlines are making available as awards to their partners (except it does not show you availability on Swiss or Air China). That's pretty much going to be a 100% match with what all Star Alliance airlines then offer to their members -- except United.

Go to the United forum here on Flyertalk and search for 'starnet'.

Lufthansa *is* offering the award seat to their partners. United just refuses to book it, and their agents say/think it is not available which isn't true. United is filtering out/blocking those seats from being booked to save money.

This is especially common with Lufthansa, and also with Thai Airways Europe - Asia, but creeps up on other routes and carriers as well.

Used to be much easier than it is today to get an agent to do a 'manual sell' where they send a message to the airline requesting the award space, and since the award space is available it comes back quickly as confirmed. But UA agents aren't allowed to do this, have gotten memos about it, and can be fired if they do.

Your best bet is to either (a) search for award space on carriers other than Lufthansa, or to try back -- sometimes the inventory will open back up / United will stop blocking, perhaps (one theory) they reach a quota in a given period of time and then lock down the award space.

So bottom line is this is not a problem with the tool. And it is not something you are doing wrong, other tran trying to redeem miles via United MIleage Plus when UA doesn't want you to.

If you were calling up US Airways or bmi or another Star carrier they would most likely happily book these flights for you. ^