Hank,
Yes, I'm indeed talking about the Mopar RB1 nav system. With CD's in the CD Changer, there's no way I can get silence while using the Nav system. It's always in one of three modes: AM, FM, or CD Changer.
As I said, when I don't have a magazine in the changer, I can select the CD-C mode (press 2), then return to the Nav screen (press 5), and I'll have silence behind the voice prompts.
I suspect you're using it without a CD Changer, and when it's silent, you have the unit in CD-C mode.
If I'm wrong, please let me know how you're disabling the other audio.
I can also confirm that our unit will NOT play DVD's. I tried - it did absolutely nothing. I've heard rumors that the European version does in fact play DVDs, and that it's a software "lockout" on the US version, due to our laws concerning video playback devices within view of the driver. That part is speculation, however.
BTW - Task, I had my changer mounted underneath the driver's seat, with the opening facing out towards the door. It will clear with the power seat (barely, but it does). This way it doesn't eat into your storage space.
(You could also put it under the passenger seat, but you'd have to lose the factory jack [no big loss] and tools).
Tom