Im loving the book Chad, just taking a while for Matrix Multiplication to sink in, and Transformations! :)
BTW - Do you use the Anal ISROT (http://xnaessentials.com/forums/t/92.aspx) on each object seperately e.g:
2 objects, so i apply the ISROT to the 1st object, THEN another ISROT to the 2nd? Or do i do or the Scaling first for both, then all the rotations for both etc etc etc.....