Which A2DP driver install to O2 Atom Exec is the Best?

I use the built-in A2DP driver to hear music on O2 Atom Exec, but I can't hear stereo sound from the A2DP stereo BT handfree, it is a mono sound and it usually drop the connection after receiving the call when playing music. Could anyone know that which A2DP driver install to O2 Atom Exec is the Best sound quality(stereo) and stability, thanks!