UTF-8 filenames

[bcml swiftdsl com au]

Greetings,
I am attempting to write some text to a file (and am using
bookbase.sourceforge.net as a code base. Bookbase was written with
gtk1.2). I am using gtk2 and currently have the following:

void load_config () {
  FILE *infile;
  gchar filename[128];

  strcpy ( filename, getenv("HOME") );
  strcat ( filename, "/.qconfig" );

  if (( infile = fopen ( filename, "r" )) != NULL )
  g_print ( "infile: %s\n", infile );
        if ( infile == !NULL)
  //snip

}

At runtime I receive the error: "Invalid UTF-8". I have been looking
around the net (eg glib API "glib-Character-Set-Conversion.html") for a
few days to try and find a solution, I think I know why it it is not
working but can't seem to fix it.

I have tried functions such as g_filename_from_utf8 & g_locale_from_utf8 &
others but I can't seem to avoid getting the Invalid UTF-8 errors. As far
as I am aware my filesystem locale is en_AU (on Debian).

Thanks for any help (or code examples),
bcml swiftdsl com au