I have figured out a problem with using the auxilary (headphone jack) in my truck connected to my radio deck while mounted on the GPS mount.
Problem : Only will get sound out of Right or Left side of the vehicle not both like you should
Why: I figured it out accidently but when the droid is not in the gps mount it works fine, therefore I assume that the magnets inside the gps mount are interfering with the audio output of the phone.
Solution: Dont use the GPS mount when listning to music with the droid.
I thought this may help some people with the same problem I was having.