While in main menu of the Navigation mode (where the icons for "View Map", "Navigation", "Voice Search", "Contacts", and "Search" are located), I selected the "menu" button next to the home key (the phone's buttons not a soft button on the screen) and discovered that there is an option for, "Dock Settings". Selecting that brings up, "Audio" but I can't make any adjustments to it. What is this setting? Anyone?