[JKT]

The zoom will occur to fit the contents. I would guess that when the page did not fill the vertical height of your monitor, it was because the contents of the site you visited were less than the height of the display. If you are viewing a page that exceeds the vertical height of your display area, then the zoom button should fit the vertical height of your display (you might have to click more than once as it toggles between two views - the last size of the window and the full size of the contents). This is consistent with the Apple Guidelines.

However, way back in OmniWeb 4.x days you used to be able to press modifier keys that would allow you to modify this behaviour so that e.g. the window would zoom to fit the horizontal content only and not the vertical content, and vice versa. Unless someone from OmniGroup wants to say any different, the only one that still exists (as far as I can tell.. I can't remember the other key-click combinations any more as I never used them) is the shift-clicking of the Zoom button which makes the window fill the screen.