[jQuery] jQuery.ui modal dialog with themeroller theme?

I'm finding that if I use any of the themes generated by the ui themeroller, I
cannot use them with a modal dialog. The form elements cannot receive
focus.. But if I switch to a non-modal dialog everything works.
Anyone know any way around this? I really do need modal dialogs, but do not
understand the CSS well enough to role my own (at the moment..).
Thanks.
Shawn