I think, the issue with the Vampire ones was it was difficult to try and come up with a new spin on the Vampire Mythos which was what was required, as a lot of it has been covered by the influx of new shows and movies on Vampires (Vampire Diaries, True Blood, Twilight etc).
It took me several days just to try and come up with something a little different, and that was a struggle itself which I usually can come up with some crazy idea of a story and in the end I still feel didn't quite capture it that well what I ended up with.
Plus, their was some great ideas of pitches thrown out there that got through so was a difficult selection of some of them.
