A wag at this. A port issue?
"Apple Push Notification network setup
When MDM servers and iOS devices are behind a firewall, some network configuration may need to take place in order for the MDM service to function properly. To send notifications from an MDM server to Apple Push Notification service, TCP port 2195 needs to be open. To reach the feedback service, TCP port 2196 will need to be open as well. For devices connecting to the push service over Wi-Fi, TCP port 5223 should
http://www.google.com/url?sa=t&rct=j&q=ports%20ios%20configure%20ipad&source=web &cd=1&ved=0CC0QFjAA&url=http%3A%2F%2Fimages.apple.com%2Fipad%2Fbusiness%2Fdocs%2 FiOS_MDM.pdf&ei=5lXGUPCcJMXx0gH2wYG4BA&usg=AFQjCNFzINvs7ktT-6o6Q_l4Qk2HkpjtCA&ca d=rja
google: ports ios configure ipad
Try it on your home network where there isn't a lot of 'controls' -- network filtering , firewalls, etc.