.htaccess php extension removal not working - php

Question

I am currently using an htaccess file to remove the php extension from my website files. It is working properly on one of my websites, but not on another and we're using the same code. (but with additional redirects on the one that is broken)
The weird part is - it has been working for months and only stopped working when Media Temple updated our grid server from Debian Squeeze to Wheezy (and they claim that shouldn't have changed how the htaccess works, but not sure what other explanation there is.)
Apparently it does still redirect html files. Any ideas why?
Current code:
# BEGIN (mt) controlled settings
<IfModule !mod_fcgid.c>
AddHandler php-stable .php
</IfModule>
<IfModule mod_fcgid.c>
AddHandler fcgid-script .php
<Files *.php>
Options +ExecCGI
</Files>
</IfModule>
# END (mt) controlled settings
Options +MultiViews
RewriteEngine On
RewriteCond %{REQUEST_FILENAME} !-d
RewriteCond %{REQUEST_FILENAME} !-f
RewriteRule ^([^\.]+)$ $1.php [NC,L]
RewriteRule ^([^\.]+)$ $1.html [NC,L]
ErrorDocument 403 /error-403
ErrorDocument 404 /error-404
ErrorDocument 500 /error-500
That code is followed by our 301 Redirects.

Answer 1

The host finally figured out the issue after saying it wasn't the update to Debian's fault. This is what they said:
the recent Wheezy update to the Grid had indeed modified a few >unexpected things, including the way MIMEs are configured which is why >+MultiViews was working for [site 1], which contains only .html files, >while [site 2] was not working, which contains .php files. To correct this, I have added the following line to the ~/domains/[site 2]/.htaccess file so that it interprets .php files correctly:
AddType application/x-httpd-php .php
So the code now looks like this:
AddType application/x-httpd-php .php
# BEGIN (mt) controlled settings
<IfModule !mod_fcgid.c>
AddHandler php-stable .php
</IfModule>
<IfModule mod_fcgid.c>
AddHandler fcgid-script .php
<Files *.php>
Options +ExecCGI
</Files>
</IfModule>
# END (mt) controlled settings
Options +MultiViews
RewriteEngine On
RewriteCond %{REQUEST_FILENAME} !-d
RewriteCond %{REQUEST_FILENAME} !-f
RewriteRule ^([^\.]+)$ $1.php [NC,L]
RewriteRule ^([^\.]+)$ $1.html [NC,L]