in the CSSMenuWriter/cssmw/menu.css file, change:
ul#cssmw {
background-image: url("../cssmw_images/bg.png");
background-repeat: repeat-x;
cursor: default;
height: 30px;
list-style-type: none;
margin: 0 0 0 0;
padding: 0 25px 0 25px;
}
to:
ul#cssmw {
background-image: url("../cssmw_images/bg.png");
background-repeat: repeat-x;
cursor: default;
height: 30px;
list-style-type: none;
margin: 0 0 0 0;
padding: 0 25px 0 25px;
position: relative;
z-index: 1000;
}