Is my Proximity Sensor broken?

[carlostmac1]

So i've read up on great apps such as auto screen on to allow me to become a jedi and turn the screen on by simply waving my hand over the proximity sensors. It worked fine on my first HTC One, but unfortunately i had to have it warranted and ATT sent me a new device. Now, this reconditioned device seems to have a non working proximity sensor. However, I have smswakeup pro installed with auto screen on so does this cause a conflict? I also downloaded the android sensor box and when i test the proximity sensor it just stays at 0cm. Is this a faulty device or is there another solution. I would hate to have this device warranted again.