Ah Ha... I seems the culprit was:
<tr>
<td valign="bottom">
<table width="100%" cellpadding="14" cellspacing="0" align="center">
<tr>
<td>
{if $js_enabled}
<a href="{$js_update_link|amp}" class="SmallNote">{$lng.txt_javascript_disabled}</a>
{else}
<a href="{$js_update_link|amp}" class="SmallNote">{$lng.txt_javascript_enabled}</a>
{/if}
</td>
</tr>
</table>
</td>
</tr>
in /customer/categories.tpl
Does that make sense?