Never had any problems with ring-to-ring, extension leads, coiled up extension leads, etc. The only failure was with a Homeplug inserted into one of a twin socket where the the other half has a surge protector feeding the PC and peripherals and another twin socket backing onto it through the wall feeding all my AV gear. I moved the Homeplug to a socket 8 feet away with a longer CAT5 cable and all was well. They won't go through the meter (although I suspect that they may well work through the new digital meters). Cheapest source that I've found is Solwise.