Cyrus imap user folders

We are running cyrus imap on an OS X tiger server. I added a new user to our openldap server with a groupname that matched the name of another user, ie. username: doe, group: doe - newuser: jane, group: doe. The new user jane was then able to see all of user doe's email folders in a folder called "other users". (we use apple mail client on tiger). Not only could she see but she had full access rights to the other user's folders. Trying to remove the "other users" folder from her mail account, the folder was deleted along with all of doe's folders. When I look at acls using cyrusadm there doesn't appear to be any "group" access only user access. The only copy of the user's folders exist on a laptop that hasn't been synch'd to the imap server since before the loss was discovered. How do I get these folders back into the user doe's imap account? I changed the name of the group to doelab and it appears that the problem of seeing doe's mail has been resolved. But it seems to me you should be able to have a username and a group be the same.