I have ActiveSync enabled on my Exchange server, and it works just fine with all the other iPhones (4S and below) in the office. However, I have two users who have just gotten iPhones 5, and neither of them can connect to the Exchange server.

ActiveSync is enabled on their accounts (I checked), and I've tried clearing the ActiveSyncAllowedDeviceIDs property on their accounts so any device should be able to connect, but no luck so far. I've tried rebooting the devices (universal patch, huh?) but that didn't work either. Oddly, the devices seem to authenticate just fine, the account gets added to Mail without issue.

I don't think it's an iOS 6 issue because I've upgraded my iPhone 4 to iOS 6 and I can still get my mail. Has anyone else encountered this problem?