I have a user with an iPhone 4 that is having issues with sent appointments automatically declining.

If I send a test appointment to the user, the appointment shows declined before it ever reaches the users phone. He will still get the message indicating he has an invite. When he accepts the invite, the item goes to the calendar on the phone, but we never see it in the groupwise calendar. After the appointment is accepted, the properties of my sent appointment still shows "Declined".

Appointments sent from the phone appear to function without the same issues.

Today, I have upgraded the DSMP Server to 1.2 build 579 and upgraded his iPhone to i0S 5.0. After these changes, I see the same result.

Anyone else seen this issue? If so, what steps did you take to resolve it? I appreciate the assistance as I am stumped on this issue.