site doesnt load without www

[webosb]

I can't seem to figure this out so if anyone can help me with this issue, that would be great - I can't seem to access my page without the www part.

When I do try to access it without the www part (seems like this only happens in firefox), it will ask me to download a randomly generated filename:

filename: 8tb7bsuj (different everytime)
application/x-httpd-php

When I open it up, it's actually the code to my wordpress index.php file

My .htaccess file is:
<IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /index.php [L]
</IfModule>

My setup:
Apache/2.2.8 (Unix) mod_ssl/2.2.8 OpenSSL/0.9.7a mod_auth_passthrough/2.1 mod_bwlimited/1.4 FrontPage/5.0.2.2635 PHP/5.2.5

Anyone know how I can fix this?

[Infopro]

Whats the htaccess for? Have you tried renaming it to something else (ie: .htaccess.txt) to see if that's causing issues?

[nerbonne]

Did you look at the DNS zone files and see if there are valid entries for domain.com and not just www? I'm not sure, but I'm just throwing that out there.