Problem with AM radio reception. I have the IAM module with 6-CD changer.

What is your question?

The AM reception has some interference or background noise. The FM and CD portions work fine. I replaced the rear window (with antennas) and that helped for about a week, but now the background noise is back. I noticed that Consumer Reports had a black circle under "audio" for my 2008 Volvo. Any ideas on what might be the problem here?