kagu can use mplayer to play. mplayer works correct with a2dp.
1.Edit /etc/bluetooth/audio.conf
...
#Disable=Sink
....
[A2DP]
SourceCount=2
SBCSources=1
MPEG12Sources=0

2. Install 4 scripts:
a2dp
switchOnBT.sh
speedup
speeddown

3. create device using python script (http://wiki.bluez.org/wiki/HOWTO/AudioDevices)

import dbus
bus = dbus.SystemBus()
manager = dbus.Interface(bus.get_object('org.bluez', '/org/bluez'), 'org.bluez.Manager')
bus_id = manager.ActivateService('audio')
audio = dbus.Interface(bus.get_object(bus_id, '/org/bluez/audio'), 'org.bluez.audio.Manager')

path = audio.CreateDevice('00:11:22:33:44:55')
#audio.ChangeDefaultDevice(path) #change the device to be used by default
sink = dbus.Interface (bus.get_object(bus_id, path), 'org.bluez.audio.Sink')
sink.Connect()

4. start under user
a2dp firstrun

5. set kagu player - mplayer

Now you can use
a2dp toggle
to switch a2dp on/off

I use osso-statusbar-cpu to switch a2dp on/off