Solucionado, el error estaba aquí:
Código:
/* HACK FOR IE: to make sure the sub menus show above form controls, we underlay each submenu with an iframe */
ul.MenuBarHorizontal iframe
{
position: absolute;
z-index: 1010;
}
/* HACK FOR IE: to stabilize appearance of menu items; the slash in float is to keep IE 5.0 from parsing */
@media screen, projection
{
ul.MenuBarHorizontal li.MenuBarItemIE
{
display: inline;
f\loat: left;
background: #FFF;
}
}
He cambiado a right y ya está!!!