You need also convert your old 3.0.x header to the new 3.1.x form regarding the Keywords and Description tags:
File:
/template/yourtemplate/layout.tpl.php
the old form:
Code:
<meta name="Keywords" content="{$smarty.const.KEYWORDS}" />
<meta name="Description" content="{$smarty.const.DESCRIPTION}" />
the new form:
Code:
<meta name="Keywords" content="{$sitekeywords}" />
<meta name="Description" content="{$sitedescription}" />
Otherwise, the keywords and site description will not be published for your website.
