CEDET is a collection of features, so I'm not sure specifically which one you're talking about, but are you left-clicking or middle-clicking the mouse? The middle mouse button is more commonly bound to an 'open file' command in Emacs modes.
In any case, you can always use C-h m
to list the help for the active major mode in a buffer, along with any minor modes. Key bindings are frequently listed in this help text.
Finally, as you know a working key binding, you can trivially find out what else is bound to the same command: C-h k <working binding>
will tell you which command that key is bound to, as well as any other bindings for the same command. If there are no other bindings that are to your liking, then you can always define your own.