Offshoreigor - Rw-1 is having problems in an R22 which does not have a radar for precise ranging and, if I am correct, does not even have an artificial horizon as the aircraft is not certified for instrument flying (please correct me if I am wrong RW-1). The method suggested by RegCElley of matching height above the LS with airspeed is far more relevant in the light single engine helicopter - who cares about safe single engine speed when you are in the avoid curve all the way down?
RW-1 you dont say what sort of LS you were making approaches to and what arrangement of lights you were using to judge your approach perspective. The previous advice to scan regularly to the side during your approach to help assess your rate of closure is very valid and will avoid the 100' hover or the screaming jesus final approach.