The first time I used Google Navigation I was blown away and it was amazingly accurate. It spoke and everything. After I tried to use it again though the voice stopped. My volume is fine, I didn't change the settings on the application. I know there is a mute option, but the sound should be fully working. It is weird. It literally one day worked, the next day stopped. What's the point in a voice-navigation system without the voice? Any help would be great. Thanks!