In its ongoing efforts to put an end to a handful of bugs that came along with its latest software update, Apple has now released iOS 6.1.2 fixing the Exchange calendar related issue that would overload servers. However, the latest update of the mobile operating system for iPhones, iPads and iPod touch devices does not fix the passcode unlock bug.

As promised, Apple has included a fix for the Exchange server issue that caused iOS devices to continuously loop when synchronizing a recurring calendar meeting invitation on Microsoft Exchange. The second software update since its Jan. 28 iOS 6.1 release "fixes an Exchange calendar bug that could result in increased network activity and reduced battery life," the official change log said.

As the initial update continued to overload corporate Exchange email servers, Microsoft had released a workaround for iOS 6.1 Exchange errors including blocking and throttling iOS users.

The firmware update is currently available over the air (OTA) or through iTunes. If your device is still affected by the Exchange serve issues, you are advised to update your Apple device to iOS 6.1.2 at the earliest.

However, the passcode unlock bug from iOS 6.1 remains unfixed even with the latest iOS 6.1.2 update. Upon testing the latest update, Ars Technica reports that they are able to bypass the lock screen using the same method as described last week. "We tried the convoluted unlock exploit on our own iPhone 4S and were able to unlock the screen successfully under iOS 6.1.1, and the same process once again unlocked the phone in iOS 6.1.2, giving us access to the phone dialler app and all of the information contained within. Put simply: it doesn't look like this update fixes the passcode unlock bug, according to our testing," the report said.

The bug that allows anyone to bypass the unlock feature give access to a user's private date including iMessages, FaceTime, photos and so on.