Problem using Reporting Services forms authentication with SSL

I am using Reporting services 2005 and have enabled forms authentication using the example found in:
'C:\Program Files\Microsoft SQL Server\90\Samples\Reporting Services\Extension Samples\FormsAuthentication Sample'
This works correctly without SSL, but when I enable SSL I get an error when logging in. The symptoms are as follows. I can login to the reporting server (in my case <server>/ReportServer2) directory, but when I login to the report manager (in my case at <server>/Reports2) I get the following error:
'The underlying connection was closed: An unexpected error occurred on a send.'
Can anyone suggest why I might be getting this error?

Thank you,
Graham

Please check your RSWebApplication.config for the Entry ReportServerUrl. This should contain the correct reportserver url in this format

<UI>
<ReportServerUrl>https://<certificatename>/reportserver2</ReportServerUrl>
<ReportServerVirtualDirectory></ReportServerVirtualDirectory>