My web host recently (Sept 2011) updated their Apache servers to a newer version of Apache, and my old .htaccess
code to display extensionless URLs no longer worked. After a considerable amount of copying code (that probably worked with older versions of the Apache OS) and unsuccessfully testing, I was able to determine that the following code seems to work on my server, and several others:
Options +FollowSymLinks -MultiViews
RewriteEngine On
RewriteBase /
RewriteCond %{HTTP_HOST} !^www\.
RewriteRule ^(.*)$ http://www.%{HTTP_HOST}/$1 [R=301,L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteRule ^([^\.]+)$ $1.php [NC,L]
RewriteCond %{THE_REQUEST} ^[A-Z]+\ /([^/]+/)*[^.#?\ ]+\.php([#?][^\ ]*)?\ HTTP/
RewriteRule ^(([^/]+/)*[^.]+)\.php http://www.example.com/$1 [R=301,L]
Give that a try - the -Multiviews
seemed to be the key element to get it to work.