I'm using ZBarSDK (1.3.1) from cocoapods

Recently I upgraded my app to SDK7 and found that readerView.frame.size was 320X426 in 4-inch screen which was wrong.

After reading the source code I found that ZBarReaderViewController is hardcoding iphone screen size in loadView

(line 321)
- (void) loadView
{
self.view = [[UIView alloc]
initWithFrame: CGRectMake(0, 0, 320, 480)];
}

Hardcoding screen size is a bad idea. It should change to:
self.view = [[UIView alloc] initWithFrame: [UIScreen mainScreen].bounds];