I had similar issues with my ex-CAI QF issued RTW, I had checked all the availability but for half of the flights (QF, JL, AA) QF had different availability to what I saw on EF (or was able to simply go and book on the airline's website and see that they'd book to D). It's pretty annoying with the RTW tickets as they are so much easier to plan and update when you can check the flights in advance.