I was debugging a problem where jQuery loading seemed to be happening at the wrong time in Chrome and IE9, so I unchecked minify. This gave me a white screen and the error logs filled with many lines that look like this:
[Fri Aug 16 11:02:18 2013] [error] [client 126.96.36.199] PHP Fatal error: Cannot call overloaded function for non-object in /var/www/biobio/wp-includes/class-wp.php on line 473 [Fri Aug 16 11:02:19 2013] [notice] child pid 5831 exit signal Segmentation fault (11)
This may have been triggered by a problem with a different plugin:
[Fri Aug 16 11:03:03 2013] [error] [client 188.8.131.52] PHP Fatal error: Only variables can be passed by reference in /var/www/biobio/wp-content/plugins/wordpress-seo/admin/ajax.php on line 17, refere
I'm going to also post on their support page.