This issue may be due to your firewall, proxy or router used in order to access the Internet.
If you're using Internet Explorer 6.x, try to toogle the following parameter: Use Passive FTP (for firewall and DSL modem compatibility).
You'll find this one under Tools / Internet Options / Advanced. Once made, validate, close all your IE windows and make a new try.
If you always face this problem, please send an e-mail to our technical support team ( support@pointdev.com ) and one will send you a response with a direct HTTP link.