Outlook 2000 Calendars

I have a user that has created a new folder within outlook that contains calendar items. However, after giving several colleagues editor permissions to this new folder and also giving the correct permissions on his mailbox, his colleagues are able to add in his mailbox to their folder list and access this new calendar folder with no problems. This works ok for most of the colleagues, but some get the “This page cannot be displayed” message.
However – if the affected colleagues are given editor permissions to the users default calendar folder then they can access his default calendar and also the new calendar folder.
Is there a way of giving all users access to this new folder without having to give access to his default calendar?