Periodically (after several days or weekly) receiving 0x80070005 error, must delete and reconnect

Can successfully connect Sharepoint calendar to Outlook calendar.  However, after some period of time, days, maybe a week or two at most, 0x80070005 error is received.  The "fix" appears to be to delete the calendar from Outlook, reconnect the Sharepoint calendar, allow some time to "synch", and return to being able to use again - for a few days or a week. Help?