non-ASCII characters in auto-save files

[grivet]

Hello,
I write a lot of text under WinXP/Emacs/Latex, in French. For some unknown reason, emacs sometimes crashes and
I am left with an auto-save file, say #myfile#.
My problem is that, in such a file, all non ASCII characters are mangled. I can open #myfile# in Emacs, but accented e's, for instance,
appear as \303\250 or as \201\250 and similarly for all accented letters.
If I try to save #myfile# to disk, Emacs telles me it cannot encode these characters. Here is the answer I get when I do C-uC-x = on one
of the offending chars:

c-u c-x =

        character:   (4194216, #o17777650, #x3fffa8)
preferred charset: eight-bit (Raw bytes 128-255)
       code point: 0xA8
           syntax: w     which means: word
      buffer code: #xA8
        file code: not encodable by coding system emacs-mule-unix
          display: no font available

I have two questions:
    - Can Emacs be persuaded to to encode auto-save files in a more useful manner ?
    - Is there a systematic way to convert #myfile# to iso-latin-9 (or iso-latin-1) code, other than painstakingly
searching and replacing offending chars ?

Thanks in advance for your time and help
JP Grivet