At least on my 24 hour-old 3G iPhone. I plugged in the headset for the first time and it seemed to not go in all the way, getting hung up with about 1/16" gap between the "now flush" headset jack and the headset plug. I was afraid to put too much pressure on it, for fear of "jacking" it and dropping it. Well, it went in, but didn't seem to be a happy camper that first time. 