I am working in a big organsiation with several meeting rooms (resources). In Outlook 2007, when booking a meeting that was NOT free we used to get a warning on the screen that the resource is busy and can not be booked.
Today, in Outlook 2010, it sends out an invitation to all the attendees AND sends a cancellation mail for the resource, if it is busy. In other words, we are not receiving the pre-warning that the room cannot be booked.
It is kind of frustrating sending out invitations again and again. Yes - I know that you can see if the meeting room is busy or not in "Schedule" but for - whatever reason - sometimes it will not book the room regardless of it being free