So I don't have a clue about available Nokia software & tools...
My mum got one of these recently and she's having trouble with the touchscreen during calls. Even though there is a proximity sensor to turn off the display when the phone is near your ear, it doesn't work very well and she often ends up putting people on hold or hanging up etc.
On my HTC, I have an application that automatically locks the screen when I turn off the display or a phone call connects (not when the phone rings, but when you or whoever you're calling actually answers).
Is there something similar for Nokia?