Hi there,
I´m learning by the tutorial of yours (http://www.clockworkchilli.com/developers/walkthrough/isometric)
Unfortunately there must be a bug in the latest version (wade_1.5.1.js; wade.iso_1.1.3.js). I´ve change from the latest version to the old version from the witch-sample (wade_1.0.3.js; wade.iso_1.0.js).
From chapter "getting started" the grid isnt isometric. Please try it by your self and try it to the fisrt step of chapter 2 and you will see.