Forum PHP error when Upgrading to 4.0
 

I have 3.8 installed, when I run the install for 4.0 I get,
"vBulletin 4.0.3 requires PHP version 5.2 or greater. Your PHP is version 5.1.6, please ask your host to upgrade."

I have PHP 5.2 on my server, I upgraded from 5.1 and still get the error.