Probably just my ignorance, but I can't figure out how to make the Fn button (or the Preview button) do what I want. What I want is to have Fn bring up My Menu, as page 230-231 in the manual says. So I select that option, and press OK. Back out of Menu mode into shooting mode. When I press Fn, nothing happens. Same with Preview button, which page 232 says offers the same options.
It's not the button itself; if I select Viewfinder virtual horizon, for instance, it seems to work fine: press it and get the VH at the bottom of the display, press again and the normal shutter speed, f-stop, show up.
Am I missing something? Do some of these options only work in some shooting modes? I'm trying this in P.