Thanks kDR, I think I will purchase the SR227 model. My neighbor uses a few of them and does not seem to have any problem.
In response to Dave, there is no mistake, the following extract was taken from a pdf document for the PAO11 receptacle on smarthome.com : Minimum Load = 40W Lamps/Loads rated below 40W may flicker and/or operate erratically.
I am also surprised that there should be a lower limit of 40 W on these outlets because the clicking sound that we hear when the receptacle turns ON or OFF seem to indicate relay contacts. Once relay contacts are closed there should be no minimum current required.
Thank you for answering my call.