We have tried a number of solutions that we have found on the internet. All have not resolved The Out of Office attendant not working when trying to set it up in Outlook 2007, however it does work in OWA.
The latest is the we test a computer that was not on the domain, added it to the domain and installed Office 2010. Logged in as one of the users and open Outlook 2010. We get all the same results.