Bug report (see inside)

The following error message shows repeatedly in my logs (WP 3.5.1):

[Tue Mar 19 08:22:01 2013] [error] [client xxxxx] PHP Warning: Attempt to assign property of non-object in /xxxxxx/wp-content/plugins/transposh-translation-filter-for-wordpress/core/parser.php on line 680

I guess this is not critical, but there is definitely something wrong.

if ($this->lang) {
            if ($this->html->find('html', 0))
                    $this->html->find('html', 0)->lang = $this->lang;
            // add support for <meta name="language" content="<lang>">
            if ($this->html->find('meta[name=language]')) {
                $this->html->find('meta[name=language]')->content = $this->lang;
            }
        }