missing ui-widget* classes when activating widgets

missing ui-widget* classes when activating widgets


jquery UI 1.5.3 with jquery 1.2.6
I have downloaded a personalized package of jquery UI with a the "UI
darkness" theme, when opening the example page I'm missing all the
round corners ect.. when I look at the markup I see the ui-tab-nav(for
example), there's no js errors and the widget loads but no ui-widget*
or ui-corners* classes are added to the markup. shouldn't those
classes be added automatically? am i missing something?
Thanks,
Rudy Attias