[TheMostToys]

I've been playing around with the light sensor and I now understand why people complained about the feature that turned off the screen in a call and why it has been disabled. The problem is that the light sensor is not particularly sensitive in low light.

Using the "testHTCSensorDemoAP.exe" tool you can see how the light sensor reacts. It is good for brightening the screen in bright situations, but it drops to 0 (no light detected) in dim (but not dark) situations. So in this case, it would turn off the screen even if you didn't want it too (Ex: using the mute or speaker buttons or doing anything like taking notes or looking up other numbers) while on a call.