Make sure you're connecting to the right server. Go to Tools -> Accounts,
and open your Exchange account. Click the "Advanced" tab, and under
"Free/Busy Server", add "/public/" (without the quotes) to the end of the
server name. See if that helps.
If it doesn't you should make sure you have the correct server in there. A
tip from Gil Gordon:
If you are running the Win Outlook 2003 beta you can control click on the
Outlook icon in the system tray and select the "Connection Status..." menu.
Add "/public/" to the server of type "Public Folders" to get your Free/Busy
server.
If that doesn't help, see this one of Gil's tips:
Free/Busy over SSL - If the public folder server you are pointing to for
Free/Busy queries requires SSL, Entourage won¹t be able to query it securely,
so you won¹t be able to get Free/Busy information. Calendar and Contact sync
should still work.
Obviously the workaround here would be to change the server settings so it
doesn't require SSL.
Also, you must have Outlook Web Access turned ON in order to access
free/busy data.
You must have Exchange Server 2000 with SP2 or SP3 to use Entourage with it.