In Netscaler backed apache web servers’ access_log files you can only see Netscaler Ip address. For statistics calculation it is hard to determine how many unique clients visited your website. To see client’s ip adresses in log files you have to change apache config to set new log format.
Plesk 9.5.4 supports PHP version 5.2.17 and optionally you can add PHP 5.3 support. PHP 5.3 can be enabled in Home > Help Support > Updates section. But this version isn’t latest one. So we need to upgrade PHP manually.