Hi!
I am using the following combination:
Nokia N900 with the built in Mediaplayer, headphoned and the mediaplayer-
wiget and a Sony MEX-BT2600 car radio.
If I press play on my car radio, the player does not start. Pressing play in
the mediaplayer-widget also does not start playing. Only skipping in the
widget works. The track changes, but I am not able to start playing.
If clicking on the widget, the player opens and I can play. Then pausing
in the widget and control with the car radio over AVRCP works. When
pausing in the widget, a replay is not possible. I have to open the player
again.
I had the radio working with my old N82, having the player in autostart.
So start playing was possible over the car radio. But I cannot do so with
the N900.
By the way: The built in player is not very user friendly. It catches all the
sounds, that are available in the system. I have a folder "ringtones" in
the MyDocs folder. All these are visible in the player. Can I set the
search paths for the player. Is the built in player the only one, which is
controllable via AVRCP? I tried enna, but control did not work here.

I saw, the widget bug is known.
But how about using other players with the BT remote?

How can I autostart the mediaplayer on boot in background? I have to press play
in the mediaplayer-widget once after reboot, before I can control via bluetooth.
It is not possible to start via bluetooth directly after reboot.