SharePoint 2010 Calendar Syncing with Outlook 2010

I am getting an error when trying to sync some calendars with Outlook. The error is

"Task 'SharePoint' reported error (0x80070005): 'You do not have permission to view this SharePoint List (Site Name - Calendar Name). Contact the SharePoint site administrator. HTTP 302'"

This error is intermittent (开发者_如何学Pythonremoving the calendar from Outlook and re-syncing it sometimes resolves it temporarily) and does not effect all users at the same time. I have full control of the site as well as the calendar in question. I have tried breaking permission inheritance and setting unique permissions on the calendar with no change. I have checked AAM and all is correct (site is accessed the via the same URL internally and externally)

Our site uses both Forms Based Authentication and Windows Authentication. This issue is experience by users using AD (have not tried any FBA users).

Setup the URL for default and intranet (I know, I know) - just try it. We thought internet was right too - but kept hitting our heads against the wall. If it breaks something, try setting the value for all 3 zones - default, internet and intranet... may the luck be with you.

• Go into SharePoint Central Administration

• Go to Operations Under Global Configuration, select Alternate access mappings

• Choose your Alternate Access Mapping Collection from the dropdown (e.g. SharePoint - 80)

• Make the Default zone your new DNS name, including if it's SSL'ed or not (e.g. http://portal.company.com or https://portal.company.com)

They were having the same errors