Just wanted to add that I too, am having a problem with 8.59 thru 8.61. At first I had thought that it was my reader because I just bought a newer one. I had a prs-600 and right at the point 8.59 came out I bought a prs-900. When I hooked up the new reader Calibre didn't see it. I then assumed it was the reader. I've tried everything to get it hooked up, but nothing worked. Today I hooked up my old 600 reader and still Calibre didn't see it. That's when I started to look in to the Forums and found this thread.
