[AUCTeX] auto-fill: automatic line break for comments

[Jannis]

Dear Auctex users,


I use auto-fill to automatically hard-wrap (i.e. insert line breaks) 
long lines after a specific length. These are the relevant lines in .emacs:

(add-hook 'LaTeX-mode-hook 'turn-on-auto-fill)
(add-hook 'latex-mode-hook 'turn-on-auto-fill)
(add-hook 'text-mode-hook 'turn-on-auto-fill)
(setq-default fill-column 80)


This works fine. For comments it automatically inserts % signs for the 
new lines in case I type a comment. If I mark a whole region and use 
M-q, however, to correct the wrapping after some changes, comments are 
not automatically recognised, no % is inserted, and parts of the comment 
are treated as usual text. Only when I put the cursor into the same line 
again and hit M-q, the wrapping works fine. This, however, is not 
practical to change the wrapping of whole documents.

Is there any solution to this?

Thanks
Jannis