JQuery DataTable Row Grouping - Two Level Grouping Error

Hi all,
Is initialization code on http://jquery-datatables-row-grouping.googlecode.com/svn/trunk/twoLevelGrouping.html has mistake?
I meen first

sGroupLabelPrefix: "Rendering Engine - "

instead

sGroupLabelPrefix2: "CSS Class - "

I also have mistake

Cannot read property '_aData' of undefined

when I try configure 2 lvl grouping.
Can anybody help me?
Thanks.