I've got some problems with my NAV that I just don't understand.

Oftentimes it "grays out" most of my choices, particularly on the "INFO" screen. I can't get phone numbers or previous calls. Then when I call a number instead of ringing, I get this steady electronic squeal. Sometimes when I get that and someone answers, it goes away. Others, it doesn't go away even when they answer. I'll turn around and make the same call and it works fine.

Does anyone have any sort of experience with this? I've deleted and re-added my bluetooth several times and that doesn't seem to make any difference.