This weekend I had my first real run with my Iphone and Nikeplus sensor. Usually I use my iphone only when running in a treadmill, and my ipod nano for running outside, buy since this was a 21K run and had the need for a phone, just in case, I decided to use my iphone. After 6 miles, things got weird, my iphone paused the workout for no apparent reason, so I began receiving the message, pausing workout, sometimes it came back on it´s own, sometimes I had to press play again, with my wet hands to continue. I tried moving it to another pocket to avoid any contact, but, it was locked, so there was no way that I could pause it by contact.
As always, easer that you may imagine. I took the earplugs out, and voila, the problem apparently was that there was a false contact in the earplugs, I was using the earplugs included with the ipod, with them, you cand do two things while running, turn the volume up and down, and .....
PAUSE THE WORKOUT
so, my advice to you, use conventional earplugs while running, maybe you won´t be able to talk in the phone while running, but after all, this is one of the reasons to run.