When upgrading from PHP 5.2.17 to PHP 5.3 you might find that some older web applications will display warnings saying that some values are deprecated. It is best to disable the deprecated errors on each website effected, instead of server wide on the php.ini file.

Just include the following in your .htaccesss file:-
php_flag display_errors off
php_flag log_errors off

Refresh the webpage to make sure that this fixes the errors.