HTTPS not working with custom domain

[herbie]

I have a custom domain verified for my GAE app.   All works OK for HTTP so  http://www.mydomain.com maps to  http://myapp.appspot.com as expected.

But HTTPS connections fail:  https://www.mydomain.com is unreachable

screen grab:

My app at https://myapp.appspot.com is reachable and serving a valid certificate.

I've followed these  GAE instructions and my domain is verified

I've  added the required DNS records for my domain at Network Solutions

So I have no idea why http://www.mydomain.com works fine but  https://www.mydomain.com fails.

Can anyone help?

Thank you.

[herbie]

An update..   I removed my domain name form my GAE app, re-verified it and added back to the app. This has had some good effect. HTTPS now works with the naked domain eg. https://mydomain.com maps to https://myapp.appspot.com.  But https://WWW.mydomain.com is still unreachable. (Error: 35 - OpenSSL SSL_connect: SSL_ERROR_SYSCALL). 

How do I get all www.mydomain.com requests (http or https) to go to https://myapp.appspot.com?

Thanks