I have no problem. 
use strict;
use warnings;

use HTML::Widget qw( );

my ($up) = @ARGV
   or die;

my $s = chr(0xC9);

if ($up) {
   utf8::upgrade($s);    # Internally encoded as UTF-8
} else {
   utf8::downgrade($s);  # Internally encoded as iso-latin-1
}

my $w = HTML::Widget->new('widget')->method('GET');
$w->element('Textfield', 's')->label($s)->value($s);
my $form = $w->process();

binmode(STDOUT, ':utf8');
print(<<"__EOI__");
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN"
   "http://www.w3.org/TR/html4/strict.dtd">
<title>Test</title>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<p>$s</p>
$form
__EOI__

[download]
>perl 759467.pl 0 > 0.html

>perl 759467.pl 1 > 1.html

>fc /b 0.html 1.html
Comparing files 0.html and 1.HTML
FC: no differences encountered

[download]

HTML::Widget also worked fine with characters iso-latin-1 can't represent.

Please provide a minimal program to demonstrate your program.

In reply to Re^3: XML::Parser - Keep Encoding? by ikegami
in thread XML::Parser - Keep Encoding? by Doron

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.