Yes, I did have trouble shutting the FM Radio app after that and I know that the sound mutes when the speakers is used by something else and for me 8 times out of 10 the sound comes back. That is not a big problem.

I can't use the web browser, update the email app to fetch any new email or HAM (there's no sound from them) and listen to the radio. My feeling is that all cpu and all the memory is focused on the browser or the email update and that the radio app is without and that is why the sound stops. The app is left without any resources and when I restart the FM Radio app it recieves some resources.