Not able to delete duplicated folders in O365

Nov 14, 2014 at 5:47 PM
We are in the midst of a migration from Exchange 2003 to O365 with an Exchange 2010 interim server in the middle. Clients use mostly Outlook 2007 with a few 2010. In the process mailboxes are ending up with duplicate folders.
I have been using MFCMapi to remove the folders but have some that will not delete. The error I receive is MAPI_W_PARTIAL_COMPLETION == 0x00040680.
I am moving any items from the duplicate folders first so they are empty when I try to delete. For the users affected it is not every folder that will not delete. Usually just Calendar, Tasks.
I have searched on this error and all hits talk about corrupted email IN the folders and how to delete them. Nothing on the folders themselves.
Can you help?