I listen to music on my iPhone 4 while working out on stair master. After about an hour, voice control turns on by itself. I turn it off but it comes back on. Then the iPod is paused then skips couple songs. It doesn't stop. I think it has to do with headphones or something. Maybe sweat getting into headphones? This happens almost every time I work out.
Apparently this is common issue. https://discussions.apple.com/thread/2512674?start=0&tstart=0