There are certain key combinations that do not make it to Emacs from my keyboard also. They are not the same ones reported by Drew though. (Indeed, I use all 4 C-M-arrow combinations.) When I have inquired about my symptoms, folks have pointed to my BIOS as the likely culprit. (I had been thinking it might be the keyboard itself.) Since no BIOS upgrade was available for my motherboard, I have managed to work around the missing key combos.
Note that Emacs can also see the Windows Key modifier, so it might be possible to define satisfactory alternate key combinations using that. Regards, David V.
