ok my frist question is did you configure and properly run avrcp?
i have made a registry capture for nitrogen.
i will attach it here
import this into your registry,
and the next thing i would do is drop avrcp into your windows\startup folder.
and thats all you should need to do.
the registry settings attached are the settings for Nitrogen used by AVRCP
now let me explain something else.
on my phone avrcp will not Launch Nitro
or rather my Headset wont launch Nitrogen
dunno why, dont care as once nitro is launched it works perfect.
hit me up if this doesnt work.
also the tback driver, isnt (i dont think) a solution to this.
rather its a way for the phone to use the WM Bluetooth stack.
not really sure as i forgot, but i do use it.