Positional play PUZZLE books/software

I am looking for any good positional play PUZZLE books/software since I need a more interactive approach to learning this difficult subject (as opposed to just reading books and hoping to have absorbed the lessons without practice).

The positional play materials I can think of which have questions/puzzles include...

Complete Idiot's Guide to Chess by Wolffe (questions at the end of the chapters)

Silmans Reassess Your Chess Workbook and Amateur's Mind (about 150 combined)

Chess Strategy for Club Players by de Grooten (just a few questions at end of chapters, too advanced)

Naroditsky's positional play book (just a few questions at end of chapters, too advanced)

ChessCafe Puzzle Book 2 by Muller (don't know much about this book)

Chess Mentor modules (typically aimed at higher levels, not many lessons per course except maybe Silman's Roots of Positional Understanding)

Chessimo (bad reviews for Strategy portion)

Convekta software (Strategy 2.0 and the 4 Middlegame programs; quite advanced, sparse commentary in general, annoying interface) 

Appreciate suggestions/insights.  Thanks.

I don't recommend the book, as it went on the puzzle selections were sloppy, some even repeated diagrams a few pages later (I guess I only saw that once though).  My general impression was that it was rushed and not well thought out or organized to help the reader absorb what he was trying to teach.  I did squeeze some knowledge out of it, but if you do get it I don't recommend solving the puzzle sections in the way he recommends, just do each puzzle one at a time, and look up the answer immediately afterwards.  The strategic theme he gives the puzzle isn't always logical and other times it's too obvious.

For example if you're given a puzzle where you're able to sac the exchange on a bishop file and as a result will win a center pawn in what was obviously out of a Sicilian or French (the two examples he uses before you take this test), you automatically know the answer is the exchange sac. Other times it may in all objectivity be a tactical solution where you sac material for an attack, but the strategic theme was "a second front"  Other times it's very difficult to judge and when you spot the idea it feels good... but many other times you work hard on a solution only to find the answer is not at all instructive.

It was recommended to me though, so it must be good for some people.  It may be that I just didn't "click" with this author's presentation of the material at all... which I've never experienced before, but I guess is possible.

Also worth mentioning is I got the same impression from his Puzzle Book I which was tactical puzzles... put together too quickly, some puzzles poorly chosen or with rough solutions.

You might enjoy books like Leonard Barden's How Good Is Your Chess? or Raymond Keene's Discover Your Chess Strength.  In those you try to figure out moves as you go through master games and are scored based on your choices.  A brief explanation about the move then follows.  Don't know if either of those is still in print.

Ray Cheng's Practical Chess Exercises might be useful to you, as well.  It's a mix of strategic and tactical problems--some easy, some difficult.

And then there's Can You Be a Positional Chess Genius? by Angus Dunnington.  I've never actually seen that book, but the description of it sounds like it could be what you're looking for.

I would have recommended Chess Mentor, but if you find the exercises too difficult, then probably Silman's works is a good start. The workbook provides plenty of instructive puzzles to solve

Awesome.  Thanks everyone!  

Hj