We have identified a serious issue with responding to calendar invitations using an iPhone with the latest 3.0 update. When you accept an invitation, the meeting organizer sees the response coming from the first person to respond to the invitation and leaves your attendee status set to "no response". This means that using your iPhone to accept/reject calendar invitations will significantly interfere with organizing meetings.
This is only the case when iPhone users accepting from the same domain...ie "Internal Meetings".
When using the iPhoneOS 3.0 to accept an invitation, the invite gets returned to the meeting organizer as the incorrect user. It appears that meeting organizers show responses from iPhones running OS 3.0 as the first person to accept that particular invitation.
The meeting organizer sees these acceptance messages but they do not match who it actually came from:
iPhones that accept the meeting do not show “No Response”. The response that goes back to the organizer of the meeting is "User Outlook accepted" when it should say "User iPhone1/2 Accepted". the meeting organizer never sees the attendee status of iPhone 1/2 as they set the status of the first user to accept the meeting.
Initially, it looked to be an issue with just Exchange 2003 SP2 and Outlook 2007 clients. That is NOT the case. Shops using Exchange 2007 are experiencing the same problem. The problem seems limited to iPhones running the 3.x OS. The apparent remedy is to not accept invitations using your iPhone and wait for a fix from Apple. It is unknown if the problem will exist with Exchange 2010.