Macrumors reports that several threads on the Apple Support Communities forum are reporting random reboots on the iPhone 5s while using Apple’s iWork apps. Before the iPhone 5s reboots users see a full blue screen, being compared to the famous Windows “Blue Screen of Death” (BSOD).
The error appears when you simply open a document in an iWork app such as Pages and click the home button, it also appears when double-pressing the home button to enter multitasking mode or even random during regular device use.
Some users report that the reboot bug that appears while using an iWorks app can be fixes by turning off iCloud syncing for Apple’s Pages, Keynote and Numbers apps. However, that fix does not appear to address the other random reboots on the device.
The iPhone 5s may not be that stable, AllThingsD reports that a study by mobile application mangement platform Crittercism shows that iOS apps are twice as likely to crash on the new iPhone 5s as they are when running on the iPhone 5 and 5c.