Apache n'affiche pas les erreurs des page php

bonjour tous,
je viens de mettre sur pieds un serveur web httpd sous FC8, tous marchent bien sauf une petit problème, j'arrive pas a affichè les messages d'erreurs qui existent sur mes pages, vraiment c'est pénible pour debogage, je vous post mon fichier php.ini,

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
; Error handling and logging ;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

; error_reporting is a bit-field.  Or each number up to get desired error   
; reporting level
; E_ALL             - All errors and warnings (doesn't include E_STRICT)    
; E_ERROR           - fatal run-time errors
; E_RECOVERABLE_ERROR  - almost fatal run-time errors      
; E_WARNING         - run-time warnings (non-fatal errors)
; E_PARSE           - compile-time parse errors
; E_NOTICE          - run-time notices (these are warnings which often result
;                     from a bug in your code, but it's possible that it was
;                     intentional (e.g., using an uninitialized variable and
;                     relying on the fact it's automatically initialized to an
;                     empty string)
; E_STRICT          - run-time notices, enable to have PHP suggest changes     
;                     to your code which will ensure the best interoperability 
;                     and forward compatibility of your code
; E_CORE_ERROR      - fatal errors that occur during PHP's initial startup
; E_CORE_WARNING    - warnings (non-fatal errors) that occur during PHP's
;                     initial startup
; E_COMPILE_ERROR   - fatal compile-time errors
; E_COMPILE_WARNING - compile-time warnings (non-fatal errors)
; E_USER_ERROR      - user-generated error message
; E_USER_WARNING    - user-generated warning message
; E_USER_NOTICE     - user-generated notice message
;
; Examples:
;
;   - Show all errors, except for notices and coding standards warnings
;
error_reporting = E_ALL & ~E_NOTICE
; Print out errors (as a part of the output).  For production web sites,
; you're strongly encouraged to turn this feature off, and use error logging
; instead (see below).  Keeping display_errors enabled on a production web site
; may reveal security information to end users, such as file paths on your Web
; server, your database schema or other information.
display_errors = On

; Even when display_errors is on, errors that occur during PHP's startup
; sequence are not displayed.  It's strongly recommended to keep
; display_startup_errors off, except for when debugging.
display_startup_errors = Off

; Log errors into a log file (server-specific log, stderr, or error_log (below))
; As stated above, you're strongly advised to use error logging in place of
; error displaying on production web sites.
log_errors = Off

voila les lignes de dispaly error est activé. je vois pas pourquoi j'arrive pas a voir mes erreurs des pages?
merci pour votre aide