Hi Tim,
It sounds to me like you are trying too hard. Try to relax and play with the book. Have fun with the process, it should be enjoyable.
The purpose that you create when you first start with a book may not be the same purpose that you end with as you can change and redefine your purpose as you progress through the material.
Have you tried the 5 day plan outlined by Pete in a previous post? If not I strongly recommend that you do.
When I activate a book, I find that I get clues to areas that need dipping. Note that I said "areas". I find that by the time I recognize a clue from my mind or body to stop I will have passed the area that I am really interested in and have to back up a little (usually anywhere from a few paragraphs to a page or two). Mostly I play with the book and am not driven to get the info. I am also not in a hurry. Just relax. You are probably doing the steps correctly but are so caught up in the mechanics (like I was when I started PRing) that you are missing the more subtle clues your body is giving you.
Another thing you might try is Petes test outlined in a recent post. Try sitting in a quiet, darkened room with an emotionally charged book (you might want to stay away from horror stories) lit by a light. PR the book. When you activate the book try activating in the same environment (Pete didn't mention this but it makes sense to me to try it) and pay attention to what your body is trying to tell you. You may be very surprised with the results.
Let me know how it goes.
Sincerely,
Gregory