How to obtain a Secure RSS feed??

Hi,

We have a private community attached to a Google domain, we use single sign on to authenticate. Some users would like to use the RSS feeds from community. We've enabled secure syndication but the url that we get when we hit 'Get RSS' doesn't seem to be secure and we get 'The feed being requested cannot be found' when trying to add it to Google reader. Any ideas on how to fix this?

Here is an example of the feed we get: mywebsitename.com/.../rss.aspx

Thanks

Chris