I have an OSX application written in Objective-C/Cocoa using xcode. The application is quite finished, tested and sold on the App Store. 

I haven't worked on this application for some time and recently, I rebuilt it using xcode 4.3.3 on my OSX 10.7.4 and I noticed that while it builds just fine, there are some very strange visual glitches when running the application that were never seen before and occasionally, I get EXC\_BAD\_ACCESS when closing the application. All these seem to be related to the PDFKit framework I am using. I am unable to debug these problems since the glitches are just visual (nothing I can check in code) and EXC\_BAD\_ACCESS exception comes from internally allocated objects not related to my code.

The code itself haven't changed, I tried previous revisions of the code and they all exhibit the same strange behavior now. I tried running an old binary I have of the application (compiled couple of months ago) and it works just fine. Then I tried building it with previous versions of xcode, down to 4.2.1 (which I know was ok when I submitted the app to the app store) and the problems still occur.

Then I suspected this may be something specific to my environment so I built the project on different machine also with xcode 4.3.2 and OSX 10.7.4. Same results, the problems are still there.

So now I suspect that it has something to do with the OSX 10.7.4 update since this is the last thing that was changed between now and when I was able to produce a good build of the application. I am pretty puzzled to what to do next and how to identify the cause of this problem. I have an old binary that is working fine and I have a newly compiled binary of the same code revision that has problems. 

Is there any useful information I can get from the difference of these binaries? What can I do to determine the cause of these problems? What can I try next?

Thanks!

NOTE (update): I stated it above but I want to make sure it is clear. This is a Mac OSX Cocoa application, not iOS.