Lot of users reports problems with Exchange ActiveSync after upgrading IPhone or IPad to iOS6.
If you have IPhone or IPad and you upgrade your device to iOS 6, then if you want to create new ActiveSync profile on your device it fail.
The new iOS 6 has problem with populate all fields required for automatic profiles setup.
But if you already have a ActiveSync profile on your IPhone/IPad and then upgrade to iOS 6, everything works fine.
There is also another bug iOS6 with Exchange meeting invitations.
The issue appear when user with iOS 6 decline a meeting invitation.
After user decline, iOS 6 is sending meeting cancellation notices to the entire distribution list, what causes canceling the invitation for all attendees.
So users with iOS 6 are being asked no to accept or decline calendar appointments until the problem has been resolved.
Some companies are requesting theirs emloyees not upgrade to iOS 6 until a bug with Microsoft Exchange meetings invitations will be fixed.