http://www.blackberryforums.com/gene...have-a2dp.html
from srotman
"It works! It works! It works!
To ARHYTHMATIK: Not to be an ass, but sorry buddy, you're DEAD WRONG!
A2DP is not stereo specific. Newer implementations of such allow stereo transfer of sound, and I believe that is more to do with newer revisions of the Bluetooth profiles/stacks than A2DP.
Anywho, I downgraded to 4.2.2.67 and in the media player I suddenly had the option to "Activate Jawbone" or "Activate BlackBerry655", which are both NON STEREO HEADSETS!
I tested this for MP3 audio playback AND video playback of a video I converted off of YouTube.
It wouldn't play ringtones back through the headset and still rang through the speaker, but when I went into the device properties of my headsets I noticed it only listed "Headset" and it was missing the "Hands Free" profile. So I deleted the devices and repaired them. I gave a test call, and sure enough the ring came through the headset!
FINALLY!!! After almost a year of missing this feature, it's back! Now if only someone can figure out what drugs the guys over at RIM are doing to make them either accidentally or purposely remove this feature from more recent OS revisions.
To everyone out there with just a headset, and who doesn't want to drop good cash on stereo BT heaphones, you can now enjoy the full set of features the Curve has to offer, through BT, the way it is SUPPOSED TO."