Q:

Why CSS making links non-clickable in Firefox?

I'm checking in Firefox 3.6
Why 2nd level links are not clickable in this tab menu.
alt text http://shup.com/Shup/383239/11061405615-My-Desktop.png
live example here : http://jsbin.com/upeka4/5
these are clickable if disable the css

A:

Probably because the z-index definition here:
ul.level2  {
background:none repeat scroll 0 0 #F3F8C6;
border:1px solid #EABF4A;
left:0;
padding:6px;
position:absolute;
top:30px;
width:463px;
z-index:-1; <------------------------ there
}

A:

Your z-index: -1 is the problem

