* plugins/fmradio/rb-fm-radio-source.c (playing_entry_changed): only mute/unmute the radio when we need to turn it off or on. Also change the radio station locations to use an "fmradio:" prefix. (rb_fm_radio_source_add_station): prepend "fmradio:" to the radio frequency to form a URI for the entry. Also check to make sure the frequency can be parsed as a floating point number.