"iPhone 5 touch screen bug? Slide finger back and forth diagonally on screen, input events drop out or stop altogether."
Now, this would appear to be what's known as an "edge case," meaning one that won't affect the majority of users, unless they "try" to make it fail.
Reportedly, this issue does not affect the iPhone 4S, so it would appear to not be an iOS 6.0.1 or 6.0 issue. It appears that it also affects the fifth generation iPod touch.
That would seem to point to the new touchscreen technology that Apple is using in it's latest iPhone and iPod touch. Remember, as discussed earlier, Apple switched to a new - note that, new - touchscreen technology called in-cell touch panels. In-cell touch panels eliminate the need for an external module or film, which reduces the weight of the iPhone 5 as well as slimming down the panel array. In-cell touch panels can be made thinner than traditional on-cell panels, because the touch sensors are actually placed inside the color filters rather than atop them.
At issue is that while the iPhone 5 appears to keep up with vertical scrolling cues, rapid diagonal scrolling of about 45 degrees will eventually stop being detected.
However, since Apple did switch to a new touchscreen technology, we'd wonder if that is the reason behind the glitch, and if some worse issue can be someday re-created in a more user-distracting manner.
Recombu produced a video, embedded, demonstrating the behavior.