29. October 2008 15:23
I was developing a web application which uses the Exchange Web Service to schedule a meeting and to check the free/busy time of the attendees. The free busy time check was working fine and all of a sudden it stopped working. Of course there is no such thing as “all of a sudden” so after doing some backward thinking I blamed it on the Exchange Server 2007 SP1. After any hours of troubleshooting I decided to ask in the forums. Apparently this was an issue many people were having and I was mistaken in blaming the Exchange SP1. The issue started happening because of the installation of the .NET Framework 3.5 SP1. Reverting back (read the forum post on how I did it) resolved the problem which also affected the Out Of Office settings and Scheduling assistant of Outlook 2007.
So beware of the .NET Framework 3.5 SP1 on an Exchange 2007 Server. According to this forum post they are developing a patch which fixes the issue.