Why does my floyd rose special bridge keep striping the coiling off of my a string?

I have a schecter damien elite fr equipped with a floyd rose special bridge. everytime i try and pull the bar up a lot, the a strings coiling is stripped off and it pops out of the bridge. This is only a problem with the a string. Does anyone know why it does this and how to fix it? p.s. I play songs by avenged sevenfold which uses a lot of whammy for divebombs