interface orientation check in iOS6 - orientation

Question

Playing around with iOS6 today, and I got stuck on checking view frame size under various orientations, which I thought I understood in iOS5. (I understand that auto-layout solves the basic problem in many cases, but still I feel I may need this check for various reasons?).
With auto-layout off, checking the view dimensions returns the right dimension size, but not the correct edge. That is to say in portrait on the iPhone the .width property = 320 and in landscape the .width property = 300, whereas I would expect 300 to be the value of the height dimension.
This is kind of weird to me as the self.view does scale properly to the window, but another view set to the frame of the self.view does not. This would be easy to fix by checking the orientation then getting the right numbers, I guess, but am I missing something obvious, or some new rule in iOS6?
//always gives aprox 300 for width despite device orientation
-(void)willAnimateRotationToInterfaceOrientation:(UIInterfaceOrientation)toInterfaceOrientation duration:(NSTimeInterval)duration{
screenRect = CGRectMake(0, 0, self.view.frame.size.width, self.view.frame.size.height);
screenRect = self.view.window.frame;
NSLog(#"screen rect size = %f x %f", screenRect.size.width, screenRect.size.height);
[imageView setFrame:screenRect];
}
//a button to check orientation. always gives aprox 300 for width despite device orientation
- (IBAction)checkScreenSize:(id)sender {
screenRect = CGRectMake(0, 0, self.view.frame.size.width, self.view.frame.size.height);
NSLog(#"screen rect size = %f x %f", screenRect.size.width, screenRect.size.height);
screenRect = [[UIScreen mainScreen]applicationFrame];
NSLog(#"screen rect size = %f x %f", screenRect.size.width, screenRect.size.height);
}