I have an Exchange server. All of my clients are Outlook 2003. Whenever a user (all users that I've seen so far) clicks on Tools>Options>Calendar Options...>Resource Scheduling... they receive the following error:
The connection to the Microsoft Exchange Server is unavailable. Outlook must be online or connected to complete this action.
The server is up. All the clients show "Connected" in the bottom right. Mail is routing and being delivered. They can open their calendars, schedule entries, etc. However, I have several resources that are no longer accepting appointments. This seems to be related.