Your comments

I have the same issue. Sometimes, not always, the stock music player will start playing (in addition to xiaa) when I press the play button on my blue tooth headset. I think this only occurs when xiia is not the last used/active application on my phone.

The workaround for this is to remove the stock music player, but that may not be an option for everyone.

This is on a HTC Glacier, if it matters.