if i insert last comment module with no comments in joomla comments... it brokes validation xhtml check..
in the file /modules/mod_comments/mod_comments.class.php
there is 3/4 lines like this ... $html = "<SPAN class=\"small\"><i>no comments</i></SPAN>";
they must be LOWERCASE for command SPAN ... if i change SPAN to "span" all works fine.. validation pass ...
hope this help thoses who have the same problem...