We have php 5.2 as the default version of php on our shared hosting servers (as many scripts are not compatible with php version 5.4) , if you require php 5.4, or would like to test how your site / scripts runs with the new version of php, simply add the following line to a .htaccess file (in the folder where the scripts files are ) :
AddHandler application/x-httpd-php54 .php
This will then cause all scripts in that folder and folders below to parse using php 5.4
(Please note that ZendGuard and Zend Encoder and IonCube are currently NOT supported on php version 5.4 so if your script is an encoded using Zend Encoder you should use php 5.2 , if the script is encoded using IonCube or ZendGuard, then php version 5.3 can be used ) .