The strangest thing occurred several times tonight. I was listening to music using PowerAmp (a paid for app from the market) with earphones (with mic) plugged in. After having paused the music for a period of time the phone started calling and hanging up on the latest contact in my recent calls. It did this repeatedly until I unplugged the earphones. It only happened with the most recent call because that changed twice and each time it call the latest contact.