Seems like a lot of H-D owners have had intermittant problems with their H-K radios...might want to look at this PDF from Hog Tunes...but the real key is probably to contact H-K and H-D to find out if there are service hardware, software or firmware updates or bulletins to fix what appears to be an all to "familiar problem"...and don't let them tell you "--they all do it"!!!
http://www.hogtunes.com/techzone_files/software_update.pdf
http://www.hogtunes.com/techzone_files/software_update.pdf