'Unable to detect Internet Connection' when trying to register

I bought Replay Music.

Internet works fine but I am behind a proxy server. I am using the internet from this very computer. I have the proxy settings set in Internet Explorer.

I am on Windows 7 64bit

I cannot register. I enter my code and press 'enter code'

Message:
"Replay Music cannot detect your internet connection" appears... :(

In Replay Music hit the Settings button and then the Proxy tab.