Yep, I'm one of those that had problems with a Keil servo.
At that time, I used a cheap Acoms pistol TX/RX, a LRP v7.1 and a Keil PS-4001. Worked great. Then I upgraded the radio to KO Propo TX/RX FM, and the glitching hell started. The funny part was, that if I installed a cheap Acoms servo, everything worked perfect. I tried another KO Propo radio with the Keil servo, didnt worked. I moved the ariel, double checked wiring and motor caps, all the usual stuff. Nothing helped.
So I decided to get another servo and I havent got a single glitch ever since.
Schumacher Mi5 - Sanwa MT-4 / RX-462 / KO Propo PDS-2123 - Nosram 5600 X-treme Saddle Pack - LRP SPX Zero/X12 17,5 - Nosram Stealth Touch Evolution - MAAS SPS 9250