Check this out,, it seems like you are having the same problem I did, mine would try to cut off in a knife edge,, loop, etc,etc, ,it ended up being the ignition switch, flying level was ok and when I would do a sudden move or roll it would cut off, it was the ignition switch wires moving around anyway here is a link to my thread,, should be helpful,,,
http://www.rcuniverse.com/forum/m_43...tm.htm#4380868