Since moving to ios7 I am unable to distribute my app to my iPad using the ipa and provisioning profile (the same ones that worked just before I upgraded to ios7 do not work
I had a similar issue and turned out the reason was because I was trying to distribute an .ipa file without first adding the recipient device UDIDs to my developer account settings. It used to be possible in some earlier iOS versions to distribute an .ipa without adding the UDIDs but apparently not anymore. More info here: https://developer.apple.com/library/content/documentation/IDEs/Conceptual/AppDistributionGuide/TestingYouriOSApp/TestingYouriOSApp.html
And I also needed to change the code signing settings from Xcode from "iPhone developer" to "iPhone distribution".