Public Folder Access to calendar is denied

I have been denied access to a shared public calendar since updates were installed on my W7 desktop workstation using Outlook 2007.  I can access them from other  PC's, system restore did not work in an attempt to resore settings. I am the senior Admin and I am the owner and it was working last week before updates.

What could be the problem on this Windows 7 PC?

Thanks, Charlie