While no conclusive reason has yet been found for why iPhone 4 proximity sensors are failing or work intermittently, some have pointed to reports that the thickness and tinting of the glass covering the proximity sensor on the iPhone as the culprit. Some defective iPhone 4 units have much darker tinting than working models over the proximity sensor, which (as far as the assumptions go that Apple can actually fix the problem via a software update) confuses the software controlling the sensor and causes it to fail. Basically, the story goes, iPhone 4 units not made to spec are having problems because their proximity sensors are not calibrated via software properly for their physical configurations. While the true reason as to why proximity sensors are failing to work properly has not been confirmed by Apple, this version of the story has some evidence to back it up and meshes well with Apple’s own cryptic and vague statements.

So where is the software fix for all of the sporadically working proximity sensors? It looks like you will have to wait until the software update after iOS 4.1, as this coming one is going to be not doing much except prepping the way for the coming new iPod touch models. You know, the ones that are supposed to be able to FaceTime via built-in cameras. I honestly do not know here if Apple is just hoping that the proximity sensor issues will clear themselves up (in which case it would be all hardware to blame and Apple is just replacing defective units and watching suppliers more closely) or is actively working on a real software fix that just needs some more time in development.

Let me know what you think and if you are still suffering from proximity sensor issues on your iPhone 4.