My walkera radios do some thing very similar. I dont know why. i had always chalked it up to cheap components. They seem to bind solidly once they are bound though.this link is from a earlier post.
http://www.rcmodelreviews.com/spreadspectrum01.shtml these will help with the modulation thing. You messure the microwaves modulation with a good one of these.
http://en.wikipedia.org/wiki/Oscilloscope http://en.wikipedia.org/wiki/Modulation http://dictionary.reference.com/browse/modulation These a really expensive but one these would help to
http://www.google.com/products/catal...d=0CDIQ8wIwAw#