First-time user, so apologies if the answer to this is obvious, but I've searched and can't figure it out:

Using the Awards/OneWorld method, I see there there is business class award availability on IB flights, but when I go to check availability in that bucket, nothing is returned. For example, searching IB 6274 (ORD-MAD) on 6/17/12 shows CS+ under Awards/Upgrades, but when I check U inventory under the Availability tab using Amadeus I get no results.

I'm searching for U based on the chart on the website -- should I be searching in a different bucket, or is there something I'm missing?