Waiting list of suitable candidates

Hello,

I applied for the trainslation traineeship at the European Parliament for the April 2015 session. As I didn't receive a reply by 15 February, I applied for the July 2015 session. In March, they sent me an e-mail saying that I'm on a waiting list of suitable candidates, which will remain valid until 31/03/2016. Later on, they sent me an email saying that my application for the July 2015 session was unsuccessful.

Do you think that means I'm still on the list of suitable candidates? Which application prevails - the first (successful) or the second (unsuccessful) one? I don't understand why they rejected my second application if my first one was successful.

well, I would say it´s definitely still valid, if you have been already selected. I´ve read somewhere, that even if you get selected for one period, it´s not guaranteed you will be for another (due to competition, number of applicants etc.).