in reply to HTML::HTML5::Parser weirdness
As per Corion's post, make sure you're able to read the file okay — file exists, has correct permissions, etc. Try reading the file using normal Perl open, readline, etc, then sending the string to parse_string on the parser object, rather than using parse_file.
If that still doesn't work, try emailing the file to the author of that module, tobyink @ cpan.org. He can be very helpful sometimes. :)