Inconsistent Datepicker results between Firefox and IE

Inconsistent Datepicker results between Firefox and IE


I have a page that has a jQuery/UI Datepicker. Just below the date
picker is a flash object.
In IE, the datepicker comes up fine, overlaying the flash object.
However, in Firefox, the datepicker window goes under the flash
object, so you can't actually select a date.
In the datepicker.css file I am using, I have the z-index set higher
than anything else on the page...
#ui-datepicker-div {
    display: none;
    border: 1px solid #217bc0; /* Border around the date picker */
    z-index: 9999; /*must have*/
}
What am I doing wrong? Is there a way to force the datepicker to
overlay everything when it gets brought up?
Thanks for any help you can provide...