I recently upgraded my test web server to PHP 5.3.0 and ran into a couple of minor errors in the Kohana PHP Framework as a result. The first issue I found was several extensions that I use were now compiled into PHP itself. This means they were no longer in the ext directory. These included php_pdo, php_mcrypt and php_mhash. You can find the solution to that issue here. You need to make sure you comment out the lines in php.ini that attempt to include these extensions. The second issue I found was the register_globals directive in the php.ini file was depricated as of PHP 5.3. This means you should set the register_globals directive to Off in the php.ini file. This is what was tripping me up. I hope this is helpful to some of you.
