Obviously I was waiting for iOS 7 like every body else. So when it was finally released the first thing I did was download and install. However, it seems that my iPhone 4 doesn't fully support the iOS. Sometimes I can't send a text because it won't recognise that I've typed anything. The same goes with unlocking my phone and the whole thing is now super laggy.

I've tried restoring my device and resetting, but nothing. Has any one else been experiencing these problems? I've got 18 months left on my contract and don't have a fully functioning iPhone anymore. It worked fine with 6.1.3.