Default index page.

Hi Guys.

This problem isnt specifically to do with drupal, however i figure some of you will have run accross this before.

Drupal works fine when browsing to http://xxx.xxx.xxx.xxx/blog/index.php , however when browsing to http://xxx.xxx.xxx.xxx/blog/ firefox returns

"You haven chosen to open

which is a: application/x-httpd-php
from: http://xxx.xxx.xxx.xxx

What should Firefox do with this file?
Open with
Save to disk"

Now the funny thing is this doesnt happen with IE.

Now i do have index.php on the DirectoryIndex part of apaches httpd.conf, and i also have AddType application/x-httpd-php .php in httpd.conf.
I figure if there was somthing wrong with apaches configuration (aka it wasnt serving index.php as a default page), then it would effect both IE and Firefox, but this doesnt seem to be the case.

Any ideas?

(FYI, Apache 2.0.55 and PHP 5.0.5, with Drupal 4.6.5)