Able to open CRM from Browser but unable to connect through Custom code

Hi,

I have created a CRM trial instance. Inside my company network, I'm able to open this instance in browser but when I tried to connect using Organization Service Proxy it is giving me the following error:

"An unhandled exception of type 'System.InvalidOperationException' occurred in Microsoft.Xrm.Sdk.dll

Additional information: Metadata contains a reference that cannot be resolved: 'https://xxxxx.crm8.dynamics.com/XRMServices/2011/Organization.svc?wsdl&sdkversion=9'."

I tried the same code from outside network. It is working.

Initially I suspect this could be because of firewall issue but I felt if this is the case, then I should not work even through browser.

If you have any idea, please share.

Thanks,

Nithya