After upgrading to iOS 6 Beta 4 / XCode 4.4, I get the following build warning in JSONKit.m:
Direct access to objective-c's isa is deprecated in favor of object_setClass() and object_getClass()
In order to keep the code current and working in future releases (where the deprecated function is no longer supported), do you have an update that uses the new calls?
duplicate from #89
See my comment near the end for a fix.