Texinfo mode: C-u C-c C-e inserts an env instead of changing

Hi People!

When editing a Texinfo document, C-u C-c C-e inserts a new environment
instead of replacing the enclosing one.

And btw, when inserting a table, it should ask for the "bullet" to use
each item:

@table

@end table

is incorrect, @table expects a macro, such as in

@table @emph

@end table

Thanks!

Emacs  : GNU Emacs 21.3.1 (i386-pc-linux-gnu, X toolkit, Xaw3d scroll bars)
 of 2005-02-04 on trouble, modified by Debian
Package: AUCTeX 11.55

current state:
==============
(setq
 window-system 'x
 LaTeX-version "2e"
 TeX-style-path '("style/" "auto/"
		  "/usr/share/emacs21/site-lisp/auctex/style/"
		  "/var/lib/auctex/emacs21/")
 TeX-auto-save t
 TeX-parse-self t
 TeX-master nil
 )