As far as I can remember (I did measurements the last time but not this time around) the voltage on pin 3 of IC14 doesn't drop sufficiently; and this could be because it was higher to begin with. Could be that C33 doesn't get completely discharged.
Message
Re: [PolySix] Another KLM367 clone issue: MG Delay
2011-07-28 by Malte Rogacki