Problem with Resource Scheduling in Outlook

I’m trying to set up a Resource Account in Outlook. I’ve created the new user account and given the account a mailbox. I can get the mailbox open and send and receive email with no problems. However, when I go to Tools>>Options>>Calendar Options>>Resource Scheduling it tells me that the Exchange Server isn’t available (sometimes after a while and sometimes I get the error right away). Outlook says it is connected, though, and again I can send and receive email. I’ve tried taking it offline and putting it back online, but that doesn’t work either. This is Outlook 2003 on an XP machine.