The update fixes issues for iBooks and launchd and it's recommended that users who previously jailbroke their A4 devices install the Corona package from Cydia.
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).
Corona 1.0.4 online
@saurik posted version 1.0.4 of Corona in Cydia. Update now ;-)
This fixes both the launchd socket issue (last fix didn't work randomly) and iBooks.
Thanks to @xvolks for the development and @iH8sn0w for the testing.