I run quite a few of the Electrifly SS ESC's and I've had the samething happen .. and its usually caused by the BEC being overloaded and resetting which causes the RX to loose power for a fraction of a second which causes the ESC to need to be rearmed .. check for a bound servo .. could also be that the ESC is overheating how many amps is the motor pulling? But it sounds more like the BEC is resetting what servos are you running? The SS-12 only has a 1.5amp BEC and that is going to be pushing the limit if your using 4 servos even if there the micro size..