Chouby on "[Plugin: Polylang] URL trouble since 1.4.4"

:( Let's try something else.
Could you edit the file polylang/admin/settings.php at line 241 and replace:

if (3 == $this->options['force_lang'] && isset($_POST['domains']) && is_array($_POST['domains'])) {
	foreach ($_POST['domains'] as $key => $domain) {
		if (!empty($domain)) // don't store empty values. see http://wordpress.org/support/topic/url-trouble-since-144
			$this->options['domains'][$key] = esc_url_raw(trim($domain));
	}
}

by

if (3 == $this->options['force_lang'] && isset($_POST['domains']) && is_array($_POST['domains'])) {
	foreach ($_POST['domains'] as $key => $domain) {
		$this->options['domains'][$key] = esc_url_raw(trim($domain));
	}
	$this->options['domains'][$this->options['default_lang']] = get_option('home');
}

and then resave your Polylang settings again.