WordPress Specified file failed upload test

You need to add the mime type to the whitelist of allowed file types.

Assuming this one still works, you can go the plugin route using.
http://wordpress.org/extend/plugins/pjw-mime-config/

Alternatively if you want to add your own mimes in code form, here’s an example.

add_filter( 'upload_mimes', 'your_custom_mimes' );
function your_custom_mimes( $mimes ) {
    $mimes['extensionhere'] = 'mimetype/goes-here';
    return $mimes;
}

Here’s a few helpful links to help with mime types.
http://en.wikipedia.org/wiki/Internet_media_type
http://www.webmaster-toolkit.com/mime-types.shtml