How to solve SlickGrid bug in dataview example "getEditor(columnDef) is not a constructor"

In Firefox I am getting a javascript bug on one of the best SlickGrid examples http://mleibman.github.com/SlickGrid/examples/example4-model.html

It happens after the 2nd click, and her开发者_Go百科e is the report from Firebug: Any tips?

getEditor(columnDef) is not a constructor
makeActiveCellEditable(editor=-12)slick.grid.js (line 1883)
editor = -12
[Break On This Error] cancelChanges: cancelEditAndSetFocus 

http://groups.google.com/group/slickgrid/browse_thread/thread/a69628d87ada88d