Infinite SEO casuing 500 errors

i was having issues with 500 errors and thought it might have been my apache, after messing with my .htaccess file the errors were still there...sooo.. i started down the 'disable plugin' path and one by one i disabled plugins to figure out which one was causing the error.. well the second i disabled the "Infinite SEO" i got the 500 error..
from my apache error log right after i enabled the plugin..

Premature end of script headers: index.php