It seems that between version 1.8.x of JqueryUI and the current 1.9.x the structure of dependencies between jquery and jquery-ui changed as well as some of the dependencies between the jqueryui JS files and the theme CSS files.
As a result, attempting to use themes generated by the new themebuilder with older versions of jquery UI fails.
I'm rather hoping that it's possible to get to the old jqueryui themeroller somehow or that it's available for download somewhere.
Given that the entire point of theming is to allow the rapid change-out of schemes without having to overhaul other code, effectively forcing me to transition to a later version of jqueryui to continue using a theme roller strikes me as unhelpful and counterproductive.