Anyone have any idea why, when using both the Navigon and TomTom navigation apps, I am have problems getting the turn-by-turn voice prompts working consistently. It's not that I can't hear them, it's just that they aren't even being spoken?? In the Navigon MobileNavigator app, I've checked the preferences and have verified that the volume setting for the voice prompts isn't disabled. In both apps, I've double tapped the 'Home' button and have paused iPod playback (which strangely enough seems to start playing back every time I launch one of these apps even if I wasn't listening to music before hand), but again, that doesn't work and I still don't hear any voice being played back?? I've even tried uninstalling and reinstalling each of these apps, but still no dice?? Any suggestions would be greatly appreciated... Thanks!