fossman, it could be a crazy idea, but check and make sure that you've got the gyro on the tail, and it's not somehow on the main... It's probably not the case, and if it's not, then the most likely thing I think would be a problem with the ESC or something.

Oh, one more thing, I dunno if you know, but you're only supposed to have 1 bec hooked up. If you do then great =) If not cut out the red center wire that goes to the brushless esc.

while we're talking setup, you need to also have a servo splitter that will carry the signal to the 3 in 1, and also the BEC power from the 3 in 1 back to the receiver.

probably stuff you already know, but maybe something just to doubel check. I think the brushless setup starts on page 40 in the manual, it might be good to just go back over it and make sure that all of your setup is on the money. One missed setup step can happen to even the best of us =)
http://www.horizonhobby.com/ProdInfo...Pro_Manual.pdf