i think it may be just normal buzzing, i turned the EPs down to where the servo only moved like 10 degress, and the ailerons were less than half of the recommended throws...but when the stick was full left or full right it would make them buzz (kind of a mix between a hum and a high pitched noise) ... if i set the EP higher, it wouldnt do it when it passed through where the EP was before, but would do it at the new EP...thats why it seemed so strange.

I have flapperons set up..it also does it when they come down just a little bit...

Im going to assume that im probably just overreacting (first digi servos ive used) and its normal, will make a point though to bring it up when i get out to the feild thiws weekend, and let someone else hear it...