New iOS app will not install

just starting with appflow after using Phonegap build.

The Android app builds, installs and runs OK. The iOS app builds, but will not install on a provisioned iPAD. The .ipa does not try to install - its just a file like any other (there is no error)

I am trying to think of why this might happen. My only idea is that the iPad is not in the provisioning file (I will have to double check).

Are there any other possibilities?