It is in the php.ini file.

You can see the actual php.ini here:
http://nopaste.info/0d3b03ec02.html

I deleted the line out of zend.ini, but nothing happened, the page is still white.


/edit: this is the zend "zone" in phpinfo:
This program makes use of the Zend Scripting Language Engine:
Zend Engine v2.1.0, Copyright (c) 1998-2006 Zend Technologies
with the ionCube PHP Loader v3.1.32, Copyright (c) 2002-2007, by ionCube Ltd., and
with Zend Extension Manager v1.2.2, Copyright (c) 2003-2007, by Zend Technologies
with Zend Optimizer v3.3.3, Copyright (c) 1998-2007, by Zend Technologies