Hi, I have just begun my experience with Sencha Touch and unfortunatelly my learning curve is bit slow...
Please correct me if I'm wrong, but in sencha-touch-debug-with-comments.js, in line 11934:

options.params[this.nodeParam] = record ? record.getId() : 'root';

shouldn't this be:

options.params[this.nodeParam] = record ? record.getId() : this.defaultRootId;

Otherwise this parameter will not be set, and will always default to hardcoded 'root'.