200 for 404

["topinambour ####" <otpinambour@xxxxxxxxx>]

hi all

I have problems 2 years ago i use apache server
with debian, all requests 200,404,403 was ok
when i tryed urls on browser
after i use apache source with httpd.conf
exactly like:
#
# Customizable error responses come in three flavors:
# 1) plain text 2) local redirects 3) external redirects
#
# Some examples
ErrorDocument 301 " "
ErrorDocument 405 " "
ErrorDocument 304 " "
ErrorDocument 402 " "
ErrorDocument 403 " "
#  

today i use default config
#
# Customizable error responses come in three flavors:
# 1) plain text 2) local redirects 3) external redirects
#
# Some examples
#  

Only 403 gives good answer
A 404 request like:
on my network if i call my websiteand add after /:; i have an empty page
in access.logs:
192.168.0.18 - - [03/Sep/2011:19:06:08 +0200] "GET /:; HTTP/1.1" 200 20 "-" "Mozilla/5.0 (X11; U; Linux i686; fr; rv:1.9.2.17) Gecko/20110420 Firefox/3.6.17 GTB7.1"
404 request gives me a 200 request !!

here are pastebin:
http://pastebin.com/Wp88BmAP
http://pastebin.com/LUivhKpd

You can also try my website http:/lavelanet.dyndns.org and add a bad request to try to get 404  eror in browser


thank you for answer