Questions on or help for NXT books?

Recently, I received a negative rating on amazon.com for my NXT-related book Advanced NXT: The da Vinci Inventions Book where the reader complained about the comprehensibility of some of the building instructions to him and his students.
Although a negative comment is something any author has to get along with, and although I do agree with him that some of those instructions have their weak points (as a result of the trade-off I was forced to make between the depth of detail and the volume of the book), I am nevertheless grieved that he never contacted me for support on that matter - in the book, I state on various occasions that every reader is welcome to contact me via my contact page and ask for help with points that are unclear to him/her, for other questions, suggestions or in general for any feedback to the book.
Like most authors of books, it is my desire that every reader should not get frustrated but make the best from the book, and hence I try to provide help or answers to any questions that I receive via the contact page (or any other channel) as soon as possible.

So I again encourage everyone of you who has bought the book but feels the need for help: please use that way of contacting me at your leisure.

Same goes for The LEGO(R) MINDSTORMS NXT Idea Book: me and my fellow authors are grateful for any hint, suggestion or question you have regarding it - you can use our forum for that (and some readers of the book have already done and received help there).

In general, that appeals to any (NXT) book around: most of the authors have spent a lot of their time, energy and heart on them and want to see their readers taking benefit of their efforts - and after all, you spent your money for a book, so why not use that option?

Thank you,
MP