I've had similar issues... Try to get a look at the LED's right when the issue happens. My bet is that you are getting a brown-out, and the ESC is shutting off for a second. If that is the case, the red and yellow LED's will blink a couple of times after the ESC shuts off and is starting back up. My truck did this after a hard landing, wreck, etc. when the steering servo would draw a lot of amps trying to keep things in line (drawing more amps than the BEC can hope to supply). You don't happen to use a Savox servo, do you?