There's a problem when I tell Emacs to interactively check the differences
between a local file and its revision last committed in CVS.

All non-ASCII characters in the retrieved revision's buffer are displayed as
octal escapes (as though multibyte characters
were disabled), and are highlighted as being different from the
corresponding (properly displayed) characters in the local copy's buffer.

This happens when using the 'cvs-mode-idiff' command and Emacs is run with a
UTF-8 based locale setting.

The 'ediff-revision' command does the same job flawlessly, and
'cvs-mode-idiff' works as expected if using a non UTF-8 locale (e.g. env
LC_ALL=POSIX emacs).

The local file uses the iso-latin-1 encoding.

And the Emacs version is GNU Emacs 22.0.50.1 (i486-pc-linux-gnu, GTK+
Version 2.8.10) of 2006-01-16 on vernadsky, modified by Debian.