Some time ago I just realised that 404 page on my site is not that it should be, it's not even default WP 404 page - instead of it I can see
http://img827.imageshack.us/img827/3650/unlednpb.png
What I need to do to use 404.php WP file instead of this?
Here is my .htaccess
# BEGIN WordPress
<IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /
RewriteRule ^index\.php$ - [L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /index.php [L]
ErrorDocument 404 /index.php?error=404
</IfModule>
# END WordPress
And also: I am using Friendly URL, how can I remove "/index.php" from beginning of each my site's URL?