Find my iphone won't work with my ipad mini on a cellular data connection. All other apps work fine. What's wrong?

The find my iphone app is not working with my ipad mini using the cellular data connection. It will work when the wi-fi connection is active. All other apps are working fine. I've done all the usual resets and even restored my ipad software through iTunes. Still no luck. I'm thinking the find my iphone app is failed in its current edition. Any ideas?