Is there some kind of limit on how many artists/songs you can add to a station? Started an iTunes Radio Station. Started with a few artists, played fine. Added a bunch more, about 20 total. Not closely related, but all "alternative." It stopped playing. On Mac, hit play, progress bar turned to a stripe, then it would pause. Tried on iPhone, the station wouldn't start playing. Other stations played fine. Removed some artists so there were 10 total. Station now plays fine.