I have an issue where a user needs to access a shared calendar through OWA using a Windows 8 notebook. We had this same issue with Windows 7 users, which was solved by simply ensuring they weren't logging in to the light version of OWA, and then also ensuring that the page was added to the compatibility view in IE11.
The steps above do not solve the issue when using Windows 8 to access OWA. It basically continues to show the light version of the site which does not show the additional calendar. I have verified that it does work correctly when using IE11 on a Windows 7 client.
I don't suppose it's all that relevant, but we're running Exchange 2010 on SBS2011.
Any assistance will be gratefully accepted.