Problem in your css code thats why it is unaligning the other list, just change as below in your css - instead of only anchor css
.horizontalmenu li a {
font-size: 12px;
font-family: Tahoma, Geneva, sans-serif;
font-weight: lighter;
color: white;
}
.horizontalmenu li {
float: left;
margin: 5px 5px 10px 9%;
}