Out of Office assistant says the server is unavailable when trying to turn it on or off in Outlook 2007 but it works just fine in OWA. Also the Scheduling assistant is grayed out when looking up other user's schedules but it works just fine in OWA. Any ideas?

This should be because of .Net Framework 2.0 SP2 or 3.5 SP1 installed on CAS server. Check below article for further detail.http://support.microsoft.com/kb/958934You need to install .Net Framework updates according to version installed on CAS to fix the issues.http://support.microsoft.com/default.aspx/kb/959209Similar Thread:http://social.technet.microsoft.com/Forums/en-US/exchangesvrdeploy/thread/72d7084e-fd3c-4efa-b50f-c0c34c82edbf/Amit Tank | MVP - Exchange | MCITP:EMA MCSA:M | http://ExchangeShare.WordPress.com