IPhone SDK 2.2 memory corruption

Question

Hello. I'm working on an application for iPhone SDK 2.2 and seem to be having weird memory corruption problems. Not necessarily leaks because using Instruments shows my memory stamp never going above about 1.8 megs. The nature of the app is a database of animals so I'm constantly loading and unloading sounds and images. None of the objects are very large (at most I'll have 4 800k pngs loaded at once) and I've checked and rechecked my alloc/retain/release and everything is in order (hence no memory usage increase). However...after using the application for a while I'll notice strange behavior. For example:
1) we have a UILabel as the title for each page. After a while the font size of this will change.
2) I have several screens with a subclassed UIScrollView where images are loaded and then added to. The problem shows itself here by the images not showing up. there's no crash, stepping through the debugger shows that the image loads up fine, it's just that the image is not there.
3) I have a UILabel at the top of an animal description screen, which in the nib file is called "Animal Name" by default. This will change to show "Animal Name" at the top.
I've removed all audio in our latest build so that isn't the problem. What I'm starting to suspect is that altering anything defined in a nib file will cause corruption. For example, the UIScrollView is defined in the nib file, and I constantly am reassigning the contents of that with a UIImageView. This UIImageView is handled within the subview class like :
UIImageView *imgView = [[UIImageView alloc] initWithImage: [ UIImage imageWithContentsOfFile:[[NSBundle mainBundle ] pathForResource:imageToLoad ofType:@"png" ]] ];
imgView.tag = 50;
[self addSubview:imgView ];
[ imgView release ];
Then later when moving away from the screen I'll find that view's tag and remove it from the superview (since addSubView increases the retain count, the alloc+addSubView is cancelled by release+removeFromSuperView)
I can't explain why titles that are never changed would be affected, but it must somehow be related. What I'm wondering is: are there any known issues involving modification of the contents of objects defined in Nib files? Perhaps the memory allocated when initWithNibName is restrained, then any modification of objects allocated within it can cause corruption. I'm starting to think I should just alloc and free anything modified in code and skip using nib files altogether (I reset the text on buttons for example). If this is a known issue please let me know. I'll give you more information if I can.
Thank you

Answer 1

Just download the huge SDK package and install. No need to uninstall the old SDK.