I have a (non-rooted) Samsung Nexus S - Android 2.3.3 phone. It has recently started becoming completely unresponsive to my screen touches, despite many attempts, cleaning the screen etc. But if I put the phone to sleep by pressing the button on the right hand side, then press the button again to wake it up - I find it always immediately works perfectly again. It may then work perfectly for a minute or two until the same happens all over again. The problem can occur regardless of what apps I am using.
I have tried using task killer, just in case it was some side effect of one of my running apps, but it made no difference.
Any suggestions what I could try next? Or could it be an unfixable hardware problem?