Update: It appears that this was a bug and that 3.1.3 devices are now once again able to access the App Store direct on their iOS device.
iPhone and iPod touch users still running iOS 3.1.3 are now (as of the 16th December 2011) unable to directly download apps from the App Store. Instead, new updates and apps will need to be downloaded in iTunes and then synced to the iPhone or iPod.




