ARIA Problem

Dear ARIA Specialists,

I have a fundamental problem with ARIA (also not yet better in ARIA 1.1):
An element with role=listbox requres at least one descendant with role=option. But I have to implement a selectable list (listbox) that very often can be empty. The HTML solves this for static lists allowing for <ul>-elements to be without contents.

Is there some other possibility to solve the empty list problem without optimizing the definition for the listbox role?
Thanks in advance!

Ciao     Mario