Open the keypad slider (nothing to do with the camera), and hold the phone at 45 degrees. You preferably need to be outside and away from a large building, but inside can sometimes work if you are close to a large building with a clear view of quite a bit of the sky. You then need to hold the phone as still as possible for at least 30 seconds and probably closer to a minute or so. Bear in mind that 30 seconds is actually quite a bit longer than you'd think to stand holding a phone! If you follow these instructions I've not had a problem locking on anywhere. You certainly shouldn't expect it to work if you have the phone closed in your pocket while you're walking around!