Well it's 1am, I've taken my phone from my pocket and found that the screen is on and it's two minutes into a call to a friend of mine who called me earlier in the evening! This seems to happen regularly. The calls are always to the person who last called me. I think it happens when I've been playing with the phone and put it back in my pocket having forgotten to turn the screen off first. Does anyone have any solutions before my friends start blocking my number?