Kaltura installation on CentOS 6.3

Hi!

I have installed kalturaCE_v5.0.0 on CentOS 6.3 with all prerequisites
as described in http://knowledge.kaltura.com/kaltura-ce-v50-prerequisites.

Installation was succesful but when I open admin console I receive the
foollowing error:
PHP Fatal error: Class 'KalturaLog' not found in /opt/kaltura/app/admin_console/Bootstrap.php on line 17, referer: http://mydomain/start/index.php
When I open KMC, I receive:
Configuration file "/opt/kaltura/app/symfony-data/config/settings.yml, /opt/kaltura/app/alpha/apps/kaltura/config/settings.yml" does not have a registered handler, referer: http://mydomain/start/index.php

Also in kaltura_error_log I always receive the following error:
PHP Class map could not be saved to path [/opt/kaltura/app/alpha/config/../../cache//api_v3/classMap.cache] folder permisisons [777]

The first page http://mydomain/start/index.php displayed correctly

any ideas?

thanks a lot
samon