After having my Galaxy S4 for about a week I needed to use it for navigation. I input the destination into Google Maps and requested navigation from the Google Nav app. About 40 minutes later the phone located itself, and started giving me directions. Prior to that, it displayed the message "Searching for GPS..." "Use Wireless Networks" is checked in location services. I tried contacting Samsung, but customer service was not helpful. Is this problem some other software setting I don't know about, or is this likely a hardware issue that Samsung needs to fix?