Prova a sostituire tutto il css #nav con questo:
#nav {}
#navl {}
#navr {background: none;height:28px; background:url(../images/mainmenu.png) 0 0 repeat-x; font-family: segoe ui, verdana, arial, sans-serif; border:1px solid #e1e1e1;}
#nav {z-index:10; position:relative;}
#nav ul {margin:0; padding:0; float:left;}
#nav ul li {list-style:none;float:left;height:28px;position:relative; padding:0; margin:0; border-right: 1px dotted gray;}
#nav ul li a { display:block;padding:0 15px 0 15px; margin:0; line-height:28px; color:#000; text-decoration:none;font-size:11px;font-weight:normal;}
#nav ul li.active {}
#nav ul li.active a {background:url(../images/nav-a.jpg) 0 0 repeat-x}
#nav ul li:hover {}
#nav ul li a:hover{ text-decoration:none; font-weight:bold; color: #4585e6;font-size:11px;}
#nav ul li ul {position:absolute;width:180px;left:-999em;border-top:0; margin:0; padding:0;}
#nav ul li:hover ul, #menu ul li.sfHover ul {left:0;}
#nav ul li ul li {padding:0;height:auto;width:180px; margin:0; border:none;}
#nav ul li:hover ul li a {text-shadow:none;}
#nav ul li:hover ul li { background:none;}
#nav ul li:hover ul li a, #nav ul li ul li a, #nav ul li.active ul li a{margin:0; padding:0 10px;height:24px;line-height:24px; background:#1b7cb6;border-bottom:1px solid #3a3a3a;color:#d1d1d1; font-size:11px;font-weight:normal;text-shadow:none;}
#nav ul li ul li a:hover, #nav ul li ul li.active a, #nav ul li.active ul li a:hover, #nav ul li.active ul li.active a {margin:0; padding:0 0 0 10px;height:24px;line-height:24px;background:#343434;color:#fff; font-size:11px;text-shadow:none;}
#nav li ul ul {
margin: -19px 0 0 170px;
}
#nav li:hover ul ul,
#nav li:hover ul ul ul,
#nav li:hover ul ul ul ul,
#nav li.sfhover ul ul,
#nav li.sfhover ul ul ul,
#nav li.sfhover ul ul ul ul {
left: -999em;
}
#nav li:hover ul,
#nav li li:hover ul,
#nav li li li:hover ul,
#nav li li li li:hover ul,
#nav li.sfhover ul,
#nav li li.sfhover ul,
#nav li li li.sfhover ul,
#nav li li li li.sfhover ul{
z-index: 100;
left: 0;
}