It appears that iOS 6.1.3, an update mainly designed to deal with recent security compromises and the evasi0n jailbreak tool, has brought about a new round of problems for iOS device users. A quick look at the Apple support forums reveals that many iDevice owners that installed the update have been suffering from some issues, including the notorious battery drain issue that has plagued many a user on previous updates.
Many members of the Apple Support Communities forum have posted about how quickly their devices’ batteries drain following the iOS 6.1.3 installation. A few workarounds, such as performing a factory reset or turning notifications off, have not helped things that much, if at all.
Many users who tried the above workarounds claim that battery drain is still an issue despite those techniques. Battery drain has seemingly been a staple of iOS updates, such as iOS 5.0; several updates were necessitated to sort things out, but users continued to complain about their batteries draining very quickly.
It looks like Wi-Fi support is another problem that has cropped up following iOS 6.1.3. Forum members have complained about their Wi-Fi connections not working at all, or being grayed out. This was one of the bugs reported for iOS 6.0, and while that was apparently fixed on iOS 6.1.2, it looks like the issues are back with a vengeance on 6.1.3.
In the meantime, Apple has put up a support page for Wi-Fi connectivity issues; users are advised to turn off Airplane Mode if on, restart and update their iOS devices, reset network settings and use iTunes to restore their devices.