iPhone doesn't work in direct sunlight

OK, I have a weird problem for you guys. My iPhone 3G will not work in direct sunlight or when any strong light source is hitting the light/proximity sensors. Whenever you shine a bright flashlight onto the top of the phone, it freezes until the light is removed. If I'm outside, I need to cover the top of the phone to use it.

At first, I thought this was a simple software problem, but it has persisted through restore after restore.

Here's a vid.

YouTube - Broken iPhone

Now this is where it gets weird. The phone only freezes when I use an incandescent lightbulb as the source (or sunlight). If I use an LED flashlight or a fluorescent lightbulb, nothing happens and it works fine.

After reading your post, I tried the same thing with an 2G and a 3G and I get the same thing if I shine a flashlight just how it was in the video. It doesn't freeze up completely like in the video, but the screen stops responding to touch. For example, I noticed that when you shined the light, even the animation on the words "slide to unlock" freezes; mine still animate, just can't actually slide it to unlock. And when I tap the phone app, it won't respond until I take the light away. I wonder if all the proximity sensors are sensitive to light and yours is just "failing" or becoming more sensitive. I'd be interested to see a few other people try this out with theirs and post back.

Mine works just fine in direct sunlight.

EDIT - Once, the animation on the slide to unlock froze as well, until I took the light away.

Hmm...very interesting. Mine was definitely malfunctioning or something though.

I brought it to the Genius Bar and they said that they had never, ever seen anything like this. They didn't even have anything to put it under in the computer ;).

Did they replace the phone (if it was under warranty)?

I'd really like to hear of this with other iPhones. I was able to duplicate to a lesser degree the same thing, and I'm almost sure this is common among iPhones, just not as serious.

Yeah, they replaced the phone.

Perhaps the iPhone software in general has a glitch that causes it to freeze when it gets an extreme reading from the light sensor. Normally, the phone wouldn't be subjected to anything approaching an extreme value, even if you shined a flashlight directly into it, but maybe my light/proximity sensor malfunctioned and became oversensitive, thus triggering the freeze under bright light.

What this theory doesn't explain at all is the fact that my phone only froze under certain kinds of light.

still a good theory, i think.