From Bugzilla Helper: User-Agent: Mozilla/5.0 (X11; U; SunOS sun4u; en-US; rv:1.0.1) Gecko/20020921 Netscape/7.0 Description of problem: If you hold down contol shift to enter a unicode character containing the hex digit c, eg. c7 = capital c cedilla, the c won't appear, and you can't enter the character.
Actually, control-shift c is being grabbed by gnome-terminal for something else. It is confusing, but I don't suppose there is much you can do about it.
The key is bound to Edit/Copy by default, and the key binding can be changed in the keybindings editor (Edit/Keybindings...) If you don't have a menu bar, click in the terminal with the right mouse button and select "Show Menubar."