What can cause a subset of NSResponder action messages to be ignored?

Question

I have created a tiny project that consists of an NSWindowController subclass which opens its window during the app delegate's applicationDidFinishLaunching: method. There are no custom NSWindow or NSView subclasses.

I'm trying to override various NSResponder action messages. Some work, some don't.

My window controller has the methods at the bottom of the question. I am on a Macbook Pro keyboard. I see the following behavior:

• If I press the LeftArrow, I see LEFT on the console. So far so good.
• If I press Fn-UpArrow (PgUp), I see PGUP on the console. Still ok.
• If I press Fn-Ctrl-UpArrow (Ctrl-PgUp), I see PGUP on the console. This is a problem. I expected to see S_PGUP get printed.

I've tried this on 2 computers and don't believe there are any custom keybindings in effect. I also double checked this with the Keyboard Shortcuts control panel item.

While I give the example for scrollPageUp:, others are affected too (e.g. scrollToBeginningOfDocument:)

Does anyone have insight as to what might be going on?

-(IBAction)moveLeft:(id)sender
{
    NSLog(@"LEFT");
}

-(IBAction)scrollPageUp:(id)sender
{
    NSLog(@"S_PGUP");
}

-(IBAction)pageUp:(id)sender
{
    NSLog(@"PGUP");
}