David, (Thanks for your reply!)
The URL is constructed using these two lines:
ServerUrl = location.protocol + "//" + location.host + "/" + parent.Xrm.Page.context.getOrgUniqueName();
return ServerUrl + "/XRMServices/2011/OrganizationData.svc";
So as you can see, we are using the same protocol as the Contact page.
This has some up because we have a distributed organization. Our local office is using HTTP since everything is "inside the wire". But our remote offices use a VPN to access our network and it has been decided that they should access the system using HTTPS
(some of the information transmitted is of a sensitive nature) as a security measure.
Based on your question, is a site limited to one or the other protocol (HTTP or HTTPS)?
Is it simply not possible to use both?
I'm dreading having to force all user to switch to HTTPS, especially since most user access the CRM via Outlook. I think that will mean having to re-configure Outlook for all 250+ users (including the users in our remote offices!).
-tomas