When using the latest stable jQuery UI themes (1.8.10) with Yii 1.1.6 (which uses 1.8.6) the widgets don't appear (they're invisible but they're there). In order to make them visible you need to change the following line:
When using themes you want to changes some of the translations specifically to the theme while keeping the standard translations for most of the text.
Duplicating the main translation file is a headache for maintainance.
This how to provides a solution.