[jQuery] Superfish IE6 dies with opacity CSS attribute

[jQuery] Superfish IE6 dies with opacity CSS attribute

I have experimented in a variety of ways, and when I use the opacity
CSS attribute, it kills the next level of the menu in IE6, FF as
always no prob.
Thus, when I had the CSS opacity code to <ul>, <li> does not appear.
If I add it to <ul><li>, then the second level
<ul><li> <li>
does
not appear. The menu's next level does not slide down, or out...
E.g. I am adding:
.sf-menu li li {
    filter: alpha
opacity=80
;
}
to the Custom CSS field in the Joomla mod_superfishmenu module.
I am using jQuery 1.2.6 and loading all SuperFish JS after mootools.js
I have also tried add it directly to superfish.css.
Any ideas or confirmation this problem exists for others out there??
I would love to add the animation, but can't get beyond opacity.
Thx! Great script!