I suspect the way this would be dealt with will depend on how wide rangign your issue is.
The biggest thing to note will be: Does this happen ONLY on AM radio.. or do you notice it on FM radio, CD's and MP3's as well?
if its across the board and your AVC is off, to me it sounds like classic 1st gen Kizashi RF amplifier failure. (I had this with my MY10 SLS Kizashi.. took a 3rd amp replacement before it was fixed.. and that amp was from a newer model apparently)
if its ONLY Am radio on which this happnes.. then yes.. it could very well be weaker signals etc with AM radio or something like that.
Interested to know if you have this issue with all audio sources or not...
