With iOS 5 Apple is adding a significant level of security by only allowing SSL-encrypted communication in the enrollment process. If no action is taken enrolling iOS 5 devices will soon come to an end:
The solution is simple: Issue a certificate for the URL being accessed by the device e.g. https://mdm.mobilityarchitects.com. Feel free to contact us for assistance.
To verify if you are already using SSL perform a device enrollment. If the enrollment points at http you need to add a certificate to the front server. If the enrollment points to https:// you are ready for iOS 5:
Note! No action is required if you are using our hosted device management service. The service has already been updated to support SSL.