Can create paragraph with tab leaders in iBooksAuthor 2.2

I'm trying to create a numbered paragraph style with tab leaders in iBooksAuthor 2.2. I followed the steps in the help topic, but when I go to the Inspector and try to select the pop-up menu for tab leaders, it's disabled. This seems to be a known problem in earlier versions of iBooksAuthor.

Is there a workaround?

bled.