A number of readers have feedback about the Base SDK Missing error in the projects in the code files downloaded. This is due to the fact that the projects were written using the 4.0 of the SDK. I have written a little document on how to change the version number for the project. You can download the PDF from:
http://www.mediafire.com/?jc425eewixcqj6o.
Hope it helps!
Wei-Meng Lee