I thought I posted a similar problem yesterday, but must have forgot to press the submit!
With 3.3.1 and standard themes, such as twenty eleven, it seems that this plug in creates widget areas only when more than the number of side bars available.
i.e. if your theme has two side bars, and you set up a tabber-widget with two tabs you will see nothing.
If you set it up with three tabs you will see just the third tab sidebar.
So what I did was create a 'dummy' tabber with the number of sidebars of my theme, to 'use up' the 'existing' sidebars. And then I can create 'real' tabbers and see all the sidebars.