There's some weird problem on one of our PCs with Outlook 2007, Zimbra 6.0.1 and Outlook Connector 6.0.5691.1.
There are shared items fro the particular account, which can be accessed as intended via the web interface. But I cannot "mount" the shared items in Outlook. The Menu item "File" -> "open other users mailbox" (folder) is greyed out.
According to this: EnableSharingAddin - Zimbra :: Wiki
there should be a "sharing" tab in the "inbox properties" window, which isn't. Neither does exist the registry key mentioned.
I re-installed the outlook connector, but to no avail. I really do not know where to look now. And as I was trying to test the behaviour on a test machine with a fresh windows XP, it showed the same effect.
Any hints where to look?