There isn't any doubt in my mind that this is static electricity being transferred through the earbuds. One time I was sitting at my desk, and I reached for my fleece on the chair next to me and received an incredibly painful jolt through my left ear. The sound also cut out of the earbud at the same time, so I thought the driver blew out. I am now careful around the office to take off my earbuds when I move my chair or reach for anything that might have static buildup, but I still get shocked here a couple times a week.
Outside of my office, this also happens at the gym, which is a pretty dry environment this time of year. The tips I'm using fit just fine, and the flange is not directly touching the inside of my ear. I really wish this wasn't happening, as I love the sound from the earbuds. I'd rather not return them to get a comparable set from Shure or Etymotics, which would cost quite a bit more.
By the way, DrWho, I'm just down the road from you, in Chicago. You'd be more than welcome to check these out yourself if you'd like []