I've tried a few radio stations. They'll play fine for over an hour, but then abruptly stop. Most of the time, this is after I take a quick peek at the song name at RuneUI from my web browser and then either navigate to some other section, or close the tab. I think there was one time where the music just stopped without me touching RuneUI prior to it.
When the music stops, it seems to stop both audibly and connection-wise (no significant activity from ethernet). The play time continues counting from RuneUI though.
I'm using a RPi2 and have RuneUI up-to-date (did the git stash and git pull thing to fix updates, and also disabled wireless). From what I can tell, the stations themselves aren't cutting out, and my internet connection is stable as well (I've had a Kodi radio setup that played one of the streams continuously for days).
I disabled MP3 gapless support too without any change.