I have also tried to add a calendar item to my iPhone and then sync it to my Outlook. As expected, the new item fails to show up in my Outlook Calendar. But then I try to remove the item through the iTunes-Info by unclicking the 'sync' option, the item in my iPhone was then removed. When I click this option again, the item then re-appear indicating the item was actually stored in the Outlook Calendar in a secret location.
The sync function was actually functioning, but only that it was stored in a secret location, without appearing in my Outlook Calendar, and all the items in my Outlook Calendar do not appear in the iPhone.
In my Outlook option, I only have only one Outlook.pst as my Calendar.
The above issue could not be removed by re-installing both Outlook and iTunes.
Wonder if the additional details as covered in the foregoing would help.
Raymond