Why is there a difference between the open macro function and the open menu item?

I’m don’t understand why the macro open command behaves differently than the menu open drop down.

Set up these files and run from the desktop. to get this:

//Begin Macro
//Differences between the open macro and the menu command.
//Drag this macro to ImageJ and run it
wdir = File.directory;  
waitForUser("Now open A.txt from the menu");
//End Macro

A.txt =
2 2 2
5 5 0
5 2 2

It looks like the old ImageJ editor gets called in the first case. I’d like to understand when the old ImageJ editor will be called.

Thanks for your thoughts
Ron DeSpain