Originally posted by another user
The glitch which as far as we’re aware hasn’t previously been spotted by anyone, manifests itself as a dropout of touch input when quickly scrolling diagonally across the screen. [...]
Using the Mail app to clearly demonstrate the quick scrolling action, we dragged our finger back and forth diagonally from bottom right to top left on each phone’s display. Sure enough, whilst both iPhone 4S’s handled the fast paced scrolling to aplomb, one iPhone 5 struggled to hold its concentration, dropping and picking back up touch input whilst the other stopped registering input altogether.