I am able to access a shared calendar when opening it via Outlook 2003, but I am unable to do so using OWA.
I enter in https://<exchange_server>/<firstname.lastname@example.org>/<calendar> but I get a 404 page. If I enter in everything except the <calendar> it attemts to open that user but gives me a permission error. I even tried adding the /calendar to my user that was logged in and I still get the 404 error.
I am using Windows XP, Outlook 2003, and Exchange 2007.