Xlab Carbon Wing??

I forgot to mention a while back, my DH bought me the entire XLab carbonwing setup for my birthday.  I had quite a few issues mounting it.  It has to mount all the way on the back of my seat rails (terry damselfly) and there is no way it will mount on the outside of the seat rails like they are supposed to.  Its almost like the rails are too wide.  I wound up mounting one side of it on the outside of one rail and the other, on the inside of the opposite rail.  Sorry i dont have any pics, but has anybody seen this before.  I'm wondering if this has to do with my seat position.  If i could move the seat back I might be able to mount it like its supposed to be but i dont want to put a smaller stem on the bike.

Thanks