Apple has acknowledged that the iOS 5.0.1 has not fixed the problem for some device owners.
Apple has acknowledged that the iOS 5.0.1 has not fixed the problem for some device owners. Reuters

A4 untethered jailbreak has been upgraded again - the French hacker pod2g said Corona has been upgraded, which fixes both iBooks issue and launchd issue.

Pod2g said on his blog, @saurik posted version 1.0.4 of Corona in Cydia. Update now ;-)......Thanks to @xvolks for the development and @iH8sn0w for the testing.

Corona (5.0.1 untether) 1.0-4 is now out: users of redsn0w or the older packages should install. This fixes both iBooks and launchd (again), @saurik tweeted.

Just a few hours later, @saurik tweeted again, As many users don't realize that untethers only affects boot, I just released 1.0-5 of the Corona package, which forces a reboot on upgrade.

A member of iPhone Dev Team MuscleNerd revealed more details. He said on his Twitter, redsn0w 0.9.10b4 (update 4 includes the iBooks fix...thanks to @xvolks for porting it to @pod2g's corona!

The iPhone Dev Team also posted the guidance to use this update:

The b4 version of redsn0w incorporates the 5.0.1 fix for iBooks, and also for sporadic problems with launchctl. Thanks to @xvolks for merging the iBooks (sandbox) fix from @comex's github into the overall corona untether from @pod2g! As usual, you can choose to install the fix either by re-running redsn0w over your existing jailbreak (de-select Cydia if you do that), or by installing the corona package from Cydia (it's the same set of files no matter which way you choose). (Here are the redsn0w download links:redsn0w 0.9.10b4 for OS X, redsn0w 0.9.10b4 for Windows)

Last Thursday, a @xvolks said on his blog that he has patched the kernel in Corona to make iBooks work without the ugly tweak called xBooks.

At the end of 2011, the iOS 5.0.1 untethered jailbreak for non-A5 devices was released, but many problems popped up. One of those problems is the iBooks crashing error that affects users' ability to launch the iBooks app.

However, it seems the Corona update does not work smoothly.

A Twitter user edbertin said, 1.0.5 didnt reboot my device after upgrade !!!

Another Twitter user n00bznet also said, I could see them all saying it didn't work. :)

We still do not know what the problem is. But we will continue to do research and once we find something useful, we will publish them.

MUST READ: iOS 5 Untethered Jailbreak: A5 Jailbreak Approaching as Pod2g releases iPhone 4S 5.0.1 Untethered Demo Video