I'm very disappointed with this book. It keeps freezing then it will closes on me. I then must start from the beginning to find where I left off. I am unable to use the bookmark so I have to manually scroll starting from the first page. I've used this commentary for many years and have enjoyed it. (This is my first electronic version). It's one of the best lesson commentaries I've studied from. However, I am not happy with this ebook version.