iOS - Testing

[Dan Friedman]

Has anyone figured out how to send their iOS app to other users for testing?  I tried creating a new Provisioning Profile with the users Device added to it... I tried creating a Ad Hoc Distribution Provisioning Profile... I even added the device to my dev profile!  But, when you drag the app and the profile into iTunes, all you get is:

The application "myapp" was not installed on the iPhone "user's iPhone" because the signer is not valid.

I know there is a step I am missing!  Any thoughts or suggestions?

-Dan