I was used to use a Bluetooth A2DP client with Spotify on my Android Nexus S with OS 2.3.6. After installing the newest Android OS 4 Spotify app is not able anymore to react anymore on Pause/Play pressed on my Bluetooth client wich is connected via A2DP protocol. Next and Previous key is still working. Since everything works fine when using the build in music player it seems to be an issue with the Spotfy app. A bit annoying that basic functionality has changed after a OS upgrade.