Why does my EVO 3D think I am talking to it? Occasionally when biking or walking, something must be going on in my pocketses because my HTC EVO 3D keeps thinking my standard headphones are evolving into headphones with an inline mic.

Normally I will be listening to music (Winamp) and the track will start skipping around; this is long after I have locked the screen and it has gone to black. I pull out the device and the headphones icon in the notification bar now have a mouth piece sticking out of them in the icon. I look at my headphones, they certainly haven't morphed in any way. I don't have bluetooth on, no other devices are connected to cause interference.

What is going on with my phone and how can I keep it from happening? I don't mind forcing it to never be an inline mic'ed set of headphones if that option is available somehow; it's incredibly annoying 45 minutes into a ride and I would love to get this locked down.
The connector must be a bit loose (or incorrectly sized) and as it wiggles around in the socket, it hits the connectors in a way that makes the phone think it's equipped with a mic (that is, a TRRS plug instead of TRS). Try another pair of headphones or try twisting and aligning the plug/cord so that there no pull or twist in the root of the cord.