Shared Calendar with SBS2003

[swancd]

When I try and create a shared calendar using SBS2003 I do the following:

On a users PC open Outlook, go to Folder View, right click the Personal Folder - NEW FOLDER - Calendar Item then I name it and press OK but I get error that I don't have permissions to do this.

I have found a few solutions on microsoft.com but they are for exchange server - any ideas what I can do to get the above to work.

At the moment they are using the Vacation Calendar on http://companyweb

Thanks