I lost a lot of sleep over that one - but happily all is ok now.
/* make the sub menuhcss ul visible and position it beneath the main menuhcss list item */
.menuhcss ul li:hover ul {
display:block;
position:absolute;
top:21px;
/* make the sub menuhcss ul visible and position it beneath the main menuhcss list item */
.menuhcss ul li:hover ul {
display:block;
position:absolute;
top:17px;
/* style the links to be 104px wide by 30px high with a top and right border 1px solid white.
Set the background color and the font size. */
.menuhcss ul li a, .menuhcss ul li a:visited {
display:block;
text-align:left;
text-decoration:none;
height:17px;
color:#000;
border:0px none #fff;
border-width:0px 0px 4px 0px;
background:url(images/body_bg.gif) repeat;
line-height:17px;
font-size:12px; font-weight:bold;
}