As per the subject, my better half's P500 won't turn off or lock automatically any more. It stays unlocked indefinitely with the screen on. Even if I use the button to lock it, after a while the screen will light back up on the unlock screen and then not dim. Obviously this is killing the battery very quickly so not ideal.
What I've tried so far:
* Checked the screen timeout in settings and put it right down to 15 seconds
* turned phone off, left it for a while, then turned back on
* taken the battery out, left it for a while then replaced and turned back on
* tried killing apps in "Running Services" one by one and none of them seem to be the culprit
* Uninstalled the only app she's installed recently (some facebook messenger app)
But it still does it. Any more suggestions to try?