I have a breakpoint set to stop on any exception, as well as "Zombie Objects" enabled. My program crashes when I click on a checkbox which uses Binding. It tells me that performSelector:withObject: is being called on an already deallocated instance of one of my class. The stack trace that it gives me isn't useful as it's entirely code that is already compiled that I didn't write that comes from Apple. Any suggestions on how to go about debugging this?