Authorize.net error: 'Can't obtain data for your transaction.'
Solution: Most probably the problem has to do with the fact that your hosting provider uses proxy server.
Therefore, in your payment settings you need to add 2 parameters:
host:port for CURLOPT_PROXY (e.g. www.someproxyserver.com:8080)
user:password for CURLOPT_PROXYUSERPWD (e.g. my_name:secret)
You can get more info at: http://www.viart.com/proxy_settings_payment_systems.html
