After a year of fault-free driving, my 235 has decided that I've listened to the radio too much -- or something -- and the "HD" icon now constantly fuzzes in and out, with a corresponding drop in sound quality. Occasionally it will even make a little digital-sounding chirp as the sound completely dies. I'm driving exactly the same streets to work and back as always. Is this a "known issue" with the 235? Or with Harmon/Kardon radios? Or am I just unlucky?