Drupal: Rules executing custom PHP don't work

I installed the module Rules and created a rule: when content is saved, echo 1+1; is executed.

Nothing happens when I create a new content and save it.

• PHP filter is enabled
• Rules modul开发者_运维问答e is enabled
• All other conditions and actions work fine
• It works fine on local server

Is there anything wrong in the remote server (Fedora 9, PHP 5.2.9)?

Is there anything that needs to be enabled in order to allow Rules to execute custom PHP code?

I think you didn't see the output because after content is saved it echo 1+1 and immediately it redirect to the view page of newly created content. try exit(); after echo in code to see if it gives output or not.