My Blade CP has been doing the jumping in flight thing for quite some time now. I noticed that it got worse as my tail motor started to go out on me. I cannot say for sure but I think it might have something to do with an excess draw by the tail that could cause the issue. I replaced the tail motor and the problem went away as far as I could tell. Give it a shot. I know tons of people talk about hte same problem!!

Johns Sparks