WMP and Bluetooth

Dell Inspiron 5150 Windows XP Pro SP2. Using a USB dongle with BlueSoleil
Bluetooth to connect with a Motorola DC800 Bluetooth adapter attached to my
home stereo to play mp3s. The device is paired and connected to the laptop
using the stereo headphone service and SBC codec. However, WMP plays the
audio thru the notebook's speakers.
If I use either iTunes or Realplayer, the audio comes thru the home stereo
as it should. Funilly enough, if I then switch to WMP it also plays thru the
home stereo (as if it needed a kick-start).

Any ideas?
Thanks
--
johnnydownunder