Media Button Router to the rescue...

After upgrading my SamSung Galaxy SII to Android 4, the play/stereo button on my car stereo quit having the desired effect while streaming audio from Listen over bluetooth.

Thanks to this post, I found Media Button Router. Installed it, configured it to send all media controls to Listen, and it just works. Even seems more reliable than before.

Fix stuck install on Android

Application updated and got stuck on "Installing..." - I couldn't cancel, reinstall, etc.

What worked for me was to follow the advice on this page and Uninstall Updates for the Market app (#1 on the page).