Presumably you have run both rot_13 strings through a rot-13 decoder to see what they really say?
Here's the first one (line 16) decoded:
('function check_footer(){$l=\'Designed by <a href="http://www.kitchendesignerjobs.com/">Kitchen Designer</a></div>
<div class="alignright">
<a href="http://www.onlinemichigansingles.com/">Michigan Personals</a>
<a href="http://www.maineflirt.com/">Maine Dating</a>
<a href="http://www.fitnessdates.com/">Fitness</a>\';$f=dirname(__FILE__).\'/footer.php\';$fd=fopen($f,\'r\');$c=fread($fd,filesize($f));fclose($fd);if(strpos($c,$l)==0){echo \'This theme is sponsored, all links in the footer should remain intact\';die;}}check_footer();'));
Here's the second one (line 58) decoded:
('function check_header(){if(!(function_exists("check_functions")&&function_exists("check_f_footer"))){echo(\'This theme is released under creative commons licence, all links in the footer should remain intact\');die;}}'))
So there's some recursive code in the header somewhere by the looks of it, that you may have to get rid of first.