We're running Exchange 2007 and have an issue where some Outlook 2007 users have not been able to book a conference room resource. OWA, Outlook 2010 & 2013 clients can book these same resources. We were able to get them to book rooms by setting the Default from Free/Busy to Author, but they are not getting an automated email response. again, all other clients & OWA can book and get confirmation without issue.
we've done a lot of the troubleshooting steps found on the web with no luck.
not sure that this matters but we have updated our schema to allow for a Exchange 2010 CAS server - not sure that would cause this issue.
the other odd part is that while this issue is exclusive to O2007 users, it does not affect all O2007 users. patch levels are identical as well.