[AUCTeX] Noweb mode

[Zozette Milane]

Dear all,
I'am currently working on foo.Rnw files on Aquamacs.
When I open such a file, Auctex turns on a Noweb-mode which seems to be in 
conflict with my favorite cdlatex mode.
For me Noweb-mode is useless.
Is it possible to make AucTeX understand that my foo.Rnw files are pure LaTeX 
files (despite the Rnw extension) and prevent it from loading noweb mode?

Another way is to solve the conflict between Noweb and cdlatex ;-)

Nota : my foo needs to keep the Rnw extension for compilation with Sweave.

Milane ...
Keep in mind that I'am just a user who does not understand the bowels of 
Emacs:-(