So, this may be a bit old to give you an answer, but here's something I found.
I am helping my wife write a website that uses Network Solutions Shared Hosting (though this also seems to happen with other shared hosting solutions). What seems to be happening is that the way they have it set up, there is one IP shared among many sites
(all the sharing hosts on one server) that points to a proxy device. This translates all incoming requests to the proper application based on the hostname, but it sends the request to your site with http:// no matter what. Any SSL is done between the client
and the proxy. So your application code never sees https:// even if that's how the client requested it. Your code just gets http://whatever.thisisapain.com. A very quick and dirty solution I cam up with was to put the following in my global.asax.
Basically, this checks for a querystring parameter called "secure", and if it's not there, redirects to https://REQUEST?secure=true or https://REQUEST&secure-true if the request already had a querystring parameter. It is not a great solution, because unless
you change all of your links and redirects to append the secure parameter, they will get an extra redirect for every new page they go to. However, the secure parameter is preserved in a postback, so that still works.
There is probably a better solution, and ultimately, the best solution would be if these providers didn't do this, but I can't do anything about that I guess.