I had this problem when I was starting out. In the tutorial it says: In order for Plucker Viewer to add a book to its library database, the .pdb file needs to be in the MyDocs folder (or a subfolder, such as eBooks) In the development environment the path to this folder is: Kanotix/scratchbox/users/knoppix/home/knoppix/MyDocs The Kernel Concepts guys straightened me out on this, and when I created the right folder everything was smooth. What folder are you putting the books in?