I tested it out and it worked fine for me. It did take a while for the Kindle to index the guide -- it was slow turning pages for a while. But that seems to have disappeared now and the pages turn normally.
I did expect something to happen after you'd downloaded a book -- either take you to Home Page or give you some sort of message. But you just get a blank page that sits there, so I pressed the Home Page key and all was well.
Thanks for this, folks.
Jim