I am having some problem in my Nokia C7 phone. As you know this phone is using a key or slider to lock and unlock the phone or screen along with keys. But in my case this phone is behaving differently. I don’t know whether this is normal or not. When I use the slider to on the screen it just lights up and again goes back to the lock mode. However when the phone is not locked and trying to lock it the slider does not do it at all. It is not always happen. It is just the “sometime” issue. I hope that you have got it.