First off, I'm not hitting the poles with the strings. Just put some new D'addario EXP coated RWs and I'm getting an electronic popping and kind of "phasing" (not really hum) sound similar to a Jazz type PU when you move around. I'm not hitting the poles with the strings. It pops when my finger touches a pole. I'm playing a 1964 Pbass but the PUs are from 1967. Never had this problem before. Had DAs RWs on it before (not coated) and had no problem. Also had a lot of other strings and this has not been a problem. Any ideas as to what is happening? Weird mix of metals in the strings reacting to the electronics or something?