This problem does not occur under debug on IIS express, nor did it happen under debug or on Azure in release mode using RC1.
If I decorate a controller with [RequireHttps] linking to it fails within the same site under azure, even though the caller page is also under SSL.
I'm testing on an azurewebsites.net sub-domain name, so a valid SSL certificate exists.
The response is a 404 bounced direct to the browser without my error handler being called in the request pipeline.
Any ideas?