For some reason, I had trouble trying to connect my phone to the wi-fi in my house, turns out there was nothing wrong with the phone, just the connection of the router had to be reset. However, for some reason when I switched my phone on, it caused an app called WaveSecure to kick in. This is an app I installed as an anti-theft measure, which always comes on in the background when I switch my phone on but never does anything. Instead, this time it asked me to put in a pin number, but wouldn't accept any of the pin numbers I usually use. It allowed me to request a randomly selected pin to 1 of the preselected numbers in my contacts. However, when I tried to do this it claimed there was no sim card in the phone. Eventually, I decided to use the PC companion software on my phone to repair the software. Now I have to set everything up again, and for some reason even though SE's backup & restore put my wallpaper back on, it didn't put my apps back on and now I have to download them again. Some of them aren't even re-installing. Fun times! Hope everyone else can use this as a lesson. Don't bother using an app for extra security, just stick to the normal pin lock!