Sorry for taking so long to reply.
I changed some settings in Parcellite, and copy & paste seems to be working fine now. But trying to assign Ctrl+C and Ctrl+V inside C::B still gives the "KeyBinding file corrupted" error. So I'm guessing that Parcellite (or other clipboard managers) have a lock on those, and C::B puts up that error by default. Maybe it should say that those key combinations are reserved by the system, or something.