I have the same problem. Back in Jr. High I learned backflips on the tramp and backflips on skis. I also during this time period somewhere learned gainer backflips on a diving board. One day in high school on the tramp I was learning a few new grabs with the backflip. I tried a laid out mute backflip like J.P. Auclair does on Global Storming, and i landed on my neck. I haven't done a backflip since. (except a tantrum on a wakeboard which I frequently do). It isn't like I am uncordinated or anything, I can misty 10 on the tramp, front, lincoln, bio, etc, but whenever it comes to backwards rotating stuff, (backflip, cork, or dspin), I just can't do it now. Now I have my brother trying to help me re-learn a backflip (5 years later), and it is really hard to get over that mental block. We just started re-learning them for me tonight, I can get the flip but I flip from one side of the tramp to the other, tomorrow I am going to work more on staying in one place. I will let you know what I learn. I agree, they are really scarry after landing on your neck, I am going to take it slow!