.htaccess-Password is blocking cURL
You can define the HTTP Auth username and password like this:
curl -u username:password http://...This way you don't have to disable the HTTP Auth while accessing it from a browser but can access it from your script.
EDIT: If working with the PHP CURL object you can also define it as such:
curl_setopt($ch, CURLOPT_USERPWD, "$username:$password");