drop down list is not working in safari

i create a drop down list using html and css it is work in moz, chrom and opera but it is not working in safari please help me to solve this problem.
my html code is:




and my css code is:

#product_profile_drop_down{
margin: 0;
padding: 0;
}
#product_profile_drop_down ul{
margin: 0;
padding: 0;
line-height: 30px;
}
#product_profile_drop_down ul li{
margin: 0;
padding: 0;
list-style: none;
position: relative;
float:left;
}
#product_profile_drop_down ul li a{
text-decoration: none;
font-family: Arial;
text-align: center;
height: 30px;
width: 150px;
display: block;
border: 1px solid white;
color: #FFFFFF;
background: #CC0040;
text-shadow: 1px 1px #000000;
}
#product_profile_drop_down ul ul{
position: absolute;
visibility: hidden;
top: 0;
left: 260px;
}
#product_profile_drop_down ul li:hover ul{
visibility: visible;
}
#product_profile_drop_down ul li ul li:hover a{
background: #999;
color: #33FFFF;
}