When I started to read your thread I wasn't surprised to read that you have a HiTec 5645MG servo installed in your aileron. I had a similar problem with a 5645 that manifested itself ONLY after being powered up for 30 minutes or so. Servo started moving all over the place on it's own. I returned the servo to HiTec and they fixed it saying it had a BAD AMPLIFIER. I didn't loose a plane because of it because the problem showed up during setup in the shop.

I highly recommend that you turn your system on and leave it on for at least an hour on the ground moving the servos wit the transmitter every so often. If it checks good the servi should be good in the air.

I posted a thread in the transmitter/receiver/servo forum regarding this occurance with the 5645 MG. Therad is titled "Hi Tec 5645mg fails during installation" . I'd give you a link to it although I can't figure out how to do that. I guess the easiest thing to do to read that thread is to click on my login "twistawrecka" and ask to see my last 50 post's, you'll find it there.
Hope this helps!