We have 5 users using Outlook 2013 to connect to our Exchange 2007 server. None of them can view free busy information. When they log into Outlook 2010, they can see the information. All other users running Outlook 2010 can view free busy information. Is this a compatibility issue between Exchange 2007 and Outlook 2013, or some kind of free/busy publishing setting that needs to be adjusted in Exchange?
Any help would be greatly appreciated. We have plans to upgrade many more users to Office 2013, but will need to wait if it requires upgrading Exchange.
Have you tried this article in your troubleshooting, also have a look at autodiscover settings: http://support.microsoft.com/kb/982698