I have been trying to purchase a DONE4 with the online tool, but kept getting a "fare no longer available" error. I just got off the phone with AA RTW desk and was told that a memo came down on November 1 that all tickets are to be priced in USD, not the local currency, to avoid currency exhange flucations.

So, if you are having trouble booking a xONEx with the tool that could be the problem.