Be very careful - BA managed to turn the fact that I went on a jumpseat ride into a BAD thing. Believe me, they will use all the dirty tricks they can to try and belittle all the good achievements you think you have made. It's really quite astonishing.
The main reason they rejected me second time round, however, was that I'd done a degree in Biology but was now working in IT (like a lot of us here). Despite the fact I have stayed in the same job since graduating they still said that I had 'changed career too many times' and they believed that I would go off the idea of flying soon enough.