RefTex keeps asking me which file is the Master file

[Wenguang Wang]

Hi,
I have a multi-file noweb project.  The file type is .mm (to
workaround a problem of my IDE debugger).  I have also added the
following file extensions into my .emacs file:

(setq reftex-file-extensions
      '(("mm" ".mm" "nw" "tex" ".tex") ("bib" ".bib")))
(setq TeX-file-extensions
      '( "mm" ".mm" "nw" "tex" ".tex" "sty" "cls" "ltx" "texi"
"texinfo"))

And at the end of each file, I have:

%%% Local Variables:
%%% mode: Noweb
%%% noweb-code-mode: c++-mode
%%% TeX-master: "mynowebproj"
%%% End:

And in mynowebproj.mm file, the TeX-master line is:

%%% TeX-master: t

However, when I save these .mm files, or when I open TOC on these
files using RefTeX, it kept asking me which file is the Master file,
very annoying.

Can anybody help me with this?

Thanks!

-Wenguang