Unlocking Focus on wrong view ((null)) under OS X 10.7.2
http://hints.macworld.com/index.php?topic=system107&page=5 This appears to have been a bug in OS X 10.7.* (Lion) series. With zero changes to my code, the crash no-longer occurs on OS X 10.8 (Mountain Lion) complied with Xcode 4.4.1.