Archived - Appointments you create with Exchange show as Invitations on iPhone or iPod touch
In some cases, an Appointment you create in Microsoft Exchange may mistakenly be synced to your iPhone as an Invitation from someone else.
The iPhone 2.0 software uses the originator's email address to distinguish between an Appointment (an event created by you) and an Invitation (an event created by someone else). The email address is case-sensitive and must match exactly. Check that the capitalization of your email address in Exchange and your email address in your iPhone settings match. Also, check that you are using mail aliases consistently. For example, your Exchange account may use "firstname.lastname@example.org" but your iPhone settings may use "email@example.com". Change one of these to match the other.