I use opacity feature for each element of Menu and this works fine with for any browser except IE.
In my custom css i've added
ul.nice-menu li ,
#header-region ul.nice-menu li
{
opacity: .95; <----- THIS WORKS GREAT
filter: progid:DXImageTransform.Microsoft.Alpha(Opacity=90); <---- THIS DOESN"T
-ms-filter: "progid:DXImageTransform.Microsoft.Alpha(Opacity=90)";<---- THIS DOESN"T
filter: alpha(opacity=90);<---- THIS DOESN"T
}

behaviour on IE is that I can't see opacity and I can't open submenus.

Comments

add1sun’s picture

add1sun commented
Status: Active » Closed (won't fix)

I myself have not messed with opacity in IE. This is a better question for wider theming support areas than Nice menus per se.