From the message: "... Yesterday I received updated code from Ben for Professional XNA Game Programming, and it is now live on the book’s page at wrox.com. This new code replaces all of the code previously available on the book’s download site, so all readers should update as soon as possible.
The update includes bug fixes, all samples now compile on both XNA Versions and on Windows (XP and Vista) and Xbox 360. In addition, Ben also included new support for some older ATI video cards because he’s cool like that ...".What are you waiting for? Just go and download the updated files!