iPhone is capacitive and N900 is resistive. Resistive is pressure based touch, where capacitive using heat and skin texture.

I fixed my clicking noise by apply some pressure on the metal frame wih your finger and push it down againsthe screen to tighten the frame so the screen will hold to the frame better. Mine stopped clicking now

Remember, apply pressure on the edge only. Sometimes the glue came off or the frame expand during heat. Metal expand when get warmer :P