I have an app created from sample code I found online. I hooked up my iPod touch 4G to my computer and everything worked fine, app ran.
Then I hooked up my iPhone 3G to the computer, established provisioning profiles, etc. In the organizer the device shows up as a green dot, so we're good. The name of the device is right there next to the run button so that's a good sign. But when I hit run it says "build succeeded" and then goes directly to "finished running on " but nothing shows up on the app!
I've tried this with several apps now and all work on iPod touch, but none on iPhone.
Devices are running newest operating systems, 4.2 for the iPhone, Xcode version is the newest.