Running an app for the first time

The iPhone Developer Programme User Guide is a comprehensive document that leads you step-by-step through a fairly complex process of creating all the security bits and pieces that protect Apple's right for the hundred bucks I mentioned before.
The document is so comprehensive and the process is so mundane that towards the end one tends to just follow the steps without any thoughts running in the skull.
So one comes across "Now press Build&Go button" sentence in the guide and gets all excited. S/he presses the button, grabs the phone and... wait a minute... What the heck?

Your mobile device has encountered an unexpected error (0xE800003A) during the install phase: Verifying application

The organiser suggests the usual programmers trick: disconnect, reboot, reconnect. One tries this a couple of times. But grave suspicion that one's f$%^ed grows with each reboot. Some people report loosing a day to this problem. The funny thing is the solution is in the guide, a couple of pages below this point in an entirely different chapter:

In the Properties Pane of the Target Info window, enter the Bundle Identifier portion of your App ID. If you have used an
explicit App ID you must enter the Bundle Identifier portion of the App ID in the Identifier field. For example enter
com.domainname.applicationname if your App ID is A1B2C3D4E5.com.domainname.applicationname. If you have used a
wildcard asterisk character in your App ID, replace the asterisk with whatever string you choose.

Thanks Apple! And really big thanks to Chamchamcham.