Bigdaddy, well done on your dissection of the powersupply, a bit like using a hammer to crack a walnut :-) The pictures certainly give a good idea of the way the input L/C Filter is configured although without the actual board in my hands it is a little difficult to determine the values of the components involved. There are a couple of drain resistors between the Phase and Neutral lines, the center of which heads off down to the chopper transistor or FET circuitry. There is what appears to be a varistor device linking across between the mains side and the DC isolated side of the supply which could easily pass the sort of "leakage" voltage that has been measured and seen on the negative output rail of these supplies. I will ponder the pictures and see what else I can determine in due course, but at least we have "some" answers, and all in all it appears to be a relatively "standard" design of a chopper powersupply :-)