Thematic version 0.9.7.7
The thematic/page.php template contains thematic_postheader(), but not thematic_postfooter(). I'm not sure if this is intensional, but it breaks code if you're expecting open tags in the header and close them in the footer.
As a fix simply add thematic_postfooter() in page.php just before
</div><!-- #post -->
Is this a bug, or is there a reason for this. Seems like a bug to me.