can't control spotify with bluetooth when another music app is installed

[mswfiber]

Just switched from iphone to android (samsung galaxy sII skyrocket) and this is by far the most annoying thing i've come across.  when i synch my phone to my car via bluetooth something prevents the controls, both dash and steering wheel, from working with the spotify app if any other music player (doubletwist, winamp, etc) is installed.  if i remove the players, spotify work fine.  if i remove spotify and have the other two, they work just fine. in fact, with all three installed the only one with issues is spotify. WTF?  

yes, i could use spotify for everything - except they still haven't figured out how to sort local files any way but alphebetically in the app.