My phone has been shutting off randomly and I need to take it in for a software upgrade, but I haven't had the time. Now the screen won't lock unless I remove the battery and restart the phone. When I push the bottom right button to darken the screen it's fine, but when I push it again to use the phone, the screen pops up and it's not locked--I can just use it without sliding the unlock button over. Does anyone else have this problem? If so, why is it doing this? Will the software upgrade fix this problem too?