When I press control-C, I get the warning sound for an invalid key press. Also happens with control-X. This doesn't interfere with orders bound to those key combintions, it's just an unexpected "bink!"
I am pretty sure ctrl+c and ctrl+x are keybiding for the "copy unit" and "cut unit" hacks for uber. What happens when you press ctrl+v?
These are, in fact, internal use / testing key hacks for copying and pasting units. As they're not valid unless running on a server without cheats turned on, it's invalid.
I guess that means binding control-X to Patrol is going to make my life a little bit more musical. All I need is a few different notes so I can get a jaunty tune going.