I am displaying a modal view controller when I rotate landscape. I want to remove the modal view controller when I am in portrait. For some reason, my log statement doesn't appear when I go into portrait mode.

- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation {
    // Return YES for supported orientations.
    return (interfaceOrientation == UIInterfaceOrientationPortrait ||
                   interfaceOrientation == UIInterfaceOrientationPortraitUpsideDown ||
                   interfaceOrientation == UIInterfaceOrientationLandscapeLeft ||
                   interfaceOrientation == UIInterfaceOrientationLandscapeRight);
}


-(void)willAnimateRotationToInterfaceOrientation:(UIInterfaceOrientation)toInterfaceOrientation duration:(NSTimeInterval)duration {

    if (toInterfaceOrientation == UIInterfaceOrientationLandscapeLeft ||
        toInterfaceOrientation == UIInterfaceOrientationLandscapeRight) {

        NSLog(@"showing chart");
        [self presentModalViewController:landscapeChartViewController animated:NO];
    }

    if (toInterfaceOrientation == UIInterfaceOrientationPortrait ||
        toInterfaceOrientation == UIInterfaceOrientationPortraitUpsideDown) {
        NSLog(@"dismissing chart");
        [self.parentViewController dismissModalViewControllerAnimated:NO];
    }
}

You can simplify this code a bit, might help narrow it down.

 - (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation {
// Return YES for supported orientations.
return YES; // Return YES is the same as entering all interfaces.
}


-(void)willAnimateRotationToInterfaceOrientation:(UIInterfaceOrientation)toInterfaceOrientation duration:(NSTimeInterval)duration {

if (UIInterfaceOrientationIsLandscape(toInterfaceOrientation)) {

    NSLog(@"showing chart");
    [self presentModalViewController:landscapeChartViewController animated:NO];
}

if (UIInterfaceOrientationIsPortrait(toInterfaceOrientation)) {
    NSLog(@"dismissing chart");
    [self.parentViewController dismissModalViewControllerAnimated:NO];
    // self.parentViewController seems like a call FROM the modalViewController. 
    // This should be moved to the modalViewControllers implementation
}
}

Just from looking at it, I'm thinking you need to dismiss the modal view controller inside the modal view, not inside the parent view. So, you would use the landscape version inside your primary controller, and then add the "willAnimateRotation..." to the modal controller to handle the portrait rotation state.