Geez- I would think it would have to be something with the servos, as they were the only thing you changed- and given the information you posted, it would be further limited to the elevator servos- Since you recorded no fades or frame losses, I wouldn't bother replacing the receiver, as it seems to be operating properly.
When you replaced the servos, did you replace the servo extensions as well? they could be generating noise.. ???? I would definitely start with the things you've changed- You can always revert back to your "last known good setup" and replace things once at a time, but I think it likens itself to russian roulette.

BTW, The big plane behind me in the pic is my friends- it's a Comp-arf 100cc Yak in the "fantasy" scheme.

lol, I don't have those kinds of funds.... He mentioned to someone out at the field last weekend that he had around $6800 in it- NO THANKS for me!![:-]