Users upgraded to Outlook 2003 no longer have access to public fol

After upgrading several users to Office 2003, they now get an error stating
"Unable to display the folder. Microsoft Office Outlook could not access the
specified folder location. The operation failed."

There has been no changes to rights to have caused this and it is happening
to every normal user. (I am admin and it works) I assume it is rights, but
what has changed from 2000 to 2003 that they can't see it??
Any help is greatly appreciated.
--
Thomas Mock