why do all sound apps get  bluetooth button events, all at once If i have my phone (thunderbolt cyanogenmod7/2.3) connected to a bluetooth stereo and i hit the play button on the stereo, music, pandora, Subsonic, and Audible all start playing at once. pausing pauses all of them.

is there some way of controlling what apps respond to the buttons? 
is there an app to filter button events?
The app Media Button Router is just what you are looking for. The app allows you to choose the media app you wish to control with the Bluetooth forward/reverse buttons using voice prompts.

The app doesn't work perfectly with all media apps, but I find that by playing with the settings you can usually overcome problems. But when it works it is magic!