RoadMap onSelect does nor return the selected step

I'm using the roadmap to visualize the working steps in wizard like manner. Everything works fine.

I would like to make it possible to navigate by clicking the steps in the roadmap to reach previous steps faster.

The onSelect method is fired every time I click on a step. The documentation promises that there is a parameter called step which contains the currently selected step id. But the parameter list within the event parameter is empty. Where can I find the information about the selected step?

Or is the roadmap not intended for such a kind of usage?

Thanks in advance

Antje

I'm using SP12.