Virtuemart LightBox behind Navigation Menu Issue

Here's how we fixed the Virtuemart LightBox behind navigation menu issue:

Edit /components/com_virtuemart/js/slimbox/css/slimbox.css

Add a couple line to (see where the red text is):

#lbOverlay {
position: absolute;
left: 0;
width: 100%;
background-color: #000;
cursor: pointer;
z-index:1000;
}

#lbCenter, #lbBottomContainer {
position: absolute;
left: 50%;
overflow: hidden;
background-color: #fff;
z-index:1000;
}