It can happen if someone else has purchased your ticket (or put it in their basket), which has happened to a friend of mine.
It is not the 2 in basket message Stoz, it is the do not qualify.
It looks like one of our cards that we upgraded from fan card is saying this. We bought membership on 23rd after hearing they would not be valid. We did not receive an email by the way, just from hearing it on here.
Card has 15 credits and membership in history, saying does not qualify. You can see enough credits in the history on screen shot.