Re: Key sequence C-c C-f C-e uses invalid prefix characters

[Richard Stallman]

    AFAIK (21.2), define-key still isn't able to rebind an existing prefix
    key; at least I failed to load psgml when sgml-mode coming with Emacs
    was loaded first (the problem was brought to my attention by Martin
    Vidner, thanks!).

If there is really a bug here, please supply a *precise test case*
so we can move from mere discussion to productive debugging.