Strange that. You're certain the changes to /etc/php.ini saved?
Are there any other scripts running before you get to your page? It could be that errors are being turned off in one of those scripts. Also, have you checked the php.ini file to make sure display_errors only appears once?
Doesn't make sense on the surface - if you change the correct php.ini file to display_errors = on and restart apache, error reporting should be turned on. Can you paste your script?