Outlook 2007/Exchange 2010 - Cannot delete accepts from meeting requests

Some of our usersI cannotdelete accepts frommeeting requests in their inbox.As aworkaroundthey holddown the shift keyand delete the item permanently

ErrorMessage: "The item could not be moved., It iseither alreadymoved or deleted,or accesswas denied"

Tried thefollowing:

newoutlookprofile
Outlook/cleanviews
movedmailboxfrom one Exchange maildatabaseto another