That's exactly why it took me some time to understand what was going on at first. The reason for that is that when you first press alt, the focus changes to the context menu (the root of the problem), if you press it again the focus goes back to where it was earlier. Basically ALT works like a toggle.And over here - ALT-S for me - highlights the "Session" command when that combo is first pressed and then if I press the combo again - the "Studio Pro" command on the main menu is highlighted. And I can go back and forth all day long.
ALT-S <> any kind of Zoom here.
VP