updated 01:52 pm EST, Fri November 9, 2012
May be caused by touch panels
The iPhone 5 and the fifth-generation iPod touch are both showing problems with handling diagonal swipes, accounts say. While the devices should work properly with regular gestures, quick diagonals can cause response to drop off. The issue is reproducible in multiple apps, and in iOS 6, 6.0.1, and the 6.1 beta. Other devices -- like the iPhone 4S and the fourth-generation iPad -- are said to be immune.
The nature of the glitch may suggest a hardware problem, since the iPhone 5 and fifth-gen Touch each use the same 4-inch touchscreen. Most users are unlikely to be bothered by it, but it could cause trouble in games, which are more dependent on rapid gestures in multiple directions.