I installed Ubuntu 12.04, increased the max upload size in the php.ini file.
post_max_size = 1800M
upload_max_filesize = 1800M
Now with ANY php script on this server it gives me an error and doesn't allow the file to be uploaded. I know the file size above is quite large but I even get the errors on files smaller than 394KB too.
I'm guessing I mucked up something somewhere and have 45 sites running on the server now so to reinstall and start over wouldn't be a viable option.
You can see the php information page here: http://greenromproject.com/info.php