Server logs:
24.16.242.61 - - [05/Nov/2007:17:37:41 -0800] "GET /difference/C_vs_C++ HTTP/1.1" 301 42 "-" "Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8.0.12) Gecko/20070508 Firefox/1.5.0.12"
24.16.242.61 - - [05/Nov/2007:17:37:42 -0800] "GET /difference/C_vs_C HTTP/1.1" 200 2459 "-" "Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8.0.12) Gecko/20070508 Firefox/1.5.0.12"


RewriteEngine On
#Redirect http://diffen.com to http://www.diffen.com
RewriteCond %{HTTP_HOST} ^diffen.com
RewriteRule ^(.*)$ http://www.diffen.com/$1 [r=301,L]
RedirectMatch ^/$ http://www.diffen.com/difference
RewriteCond %{REQUEST_URI} ^/difference$
RewriteRule ^(.*) /difference/index.php?title=Main_Page [L]

RewriteBase /
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d

RewriteCond %{THE_REQUEST} ^[A-Z]+\ /difference/([^?\ ]+)
RewriteRule ^difference/(.+)$ /difference/index.php?title=%1 [NE,L,QSA] 

IndexIgnore */*