> I did try googling for the file, but didn't find it.


   > Thanks, I downloaded this, and I'm afraid I cannot reproduce the
   > problem.  After evaluating

   >   (autoload 'comment-out-region "comment" nil t)

   > and invoking "M-x comment-out-region", the variable comment-mode-alist
   > is defined and has a value.

   > How did you test it to be (un)defined?

Thanks for you help. I now tried to do that in a clean way, started
emacs -q loaded a minimal init file with the lines

(setq load-path (cons (expand-file-name "~/emacs/init") load-path))
(autoload 'comment-out-region "comment" nil t)

And then everything works as expected. So I presume the problem is
somewhere in my init file. I have to dig into that and see what is the
reason.


BTW I could not reproduce the freezing I reported last week, that is why
no bug report so far. Thanks again