We use suphp, which has the advantage that all PHP processes run under your own userid. That has some security advantages, such as you don't have to make your files writable to the world such as many scripts suggest. Make all your directories 755 or 750 and your files 644 or 640.
Because of this, php configuration changes needs to be done in a separate php.ini file just for yourself. Contact us through the ticket system for a copy of the complete php.ini file. Just adding the changed values will not work.
By default the php.ini value is only effective in the directory where it is. If you want the value to be avaiable recursively thorughout your website you can create a .htaccess file in your base directory with the following line
suPHP_ConfigPath /home/joe/public_html
Replace /home/joe/public_html with the path to your php.ini file.If you already have a .htaccess file just add the line.