If page includes some CSS file and it is missing - webkit treats 404 server response (usually this is HTML page with some CSS inside) as CSS. So styles from 404 page are applied to main page. I've attached two files - one is common html page which includes missing CSS file using LINK tag. Other - is server response for 404 error (in my httpd.conf I have ErrorDocument 404 /404.html ) So if you will try to open that missing css - you will see 404.html as server response (HTTP code 404 is returned)
Created attachment 29681 [details] web page with reference to missing CSS file
Created attachment 29682 [details] server response for 404 error put this page somewhere at your web server and put ErrorDocument 404 /404.html into your web server config. replace "/404.html" with reference to current file.
Duplicate of bug 15242?
*** This bug has been marked as a duplicate of 15242 ***