I know you already solved this by a reinstall, but there's a vastly simpler way for other people having the same problem. (It drove me nuts before I discovered the fix, BTW.) When you tap the screen and get all the icons, one of them is "GPS". Tap on that icon and a check mark will appear. Tap it again, and the check mark goes away. The GPS only operates when the check is there! (Once you understand it, this is a nice feature to have...)