more than likely its because your car is running to cold (due to lack of thermostat). The LPG converter gets ICE cold, enough to form ice droplets on it if your coolent teperature isnt enough to keep the converter warm. Often if it gets to cold it will stop functioning, cause hard starting and surging whilst driving.
Ive been described as a vault of usless random knowledge.
Ill take it as a complement i think.............