fill-paragraph: cursor placement under cperl-mode

[Florian v. Savigny]

Hi there,

let's say I have a paragraphs with a longer comment in cperl-mode,
such as:

 # a script that converts umlauts and ß in filenames to ascii
 # characters, sings a song on the way

and then I add something, e.g. like:

 # a script that converts umlauts and ß in filenames to ascii
 # characters, sings a song on the way, and dances various folk dances
                                                                      ^

(^ marks where the cursor is) and type M-q, Emacs will fill
the paragraph, and put the cursor at the beginning of the
reformatted paragraph:

 # a script that converts umlauts and ß in filenames to ascii characters, sings
^# a song on the way, and dances various folk dances

I find this somewhat annoying. It does not seem to happen
under any other mode, where the cursor is just left where it
was, i.e. at the end of the paragraph.

I have not been able to find any hint in the documentation,
or in my customisations of cperl-mode. Can anybody give me a
hint where the problem might lie?

Thanks a bunch!

Regards,

Florian