I actually do have a semi custom carbon fiber tail boom from an AXE, although I did notice this issue before putting on that boom, so I am somewhat ruling it out for now. I know few local guys who run trex 5&600's recommended lubing the belt, which makes sense to eliminate static, and since then I haven't had any slipping problems so I doubt thats it. I still am really skeptical about the esc though, I'll see if I can't pick up something locally and give that a try. Otherwise I know a lot of the 500 and 600 guys actually ground their tail boom and frame to the negative cable on the battery, I'm wondering if that may help too.