li :hover doesnt work in IE6

Question

hi,does any body knows how can I solve this problem my menu doesn,t show up in ie6
this the css code that I use for my menu,thanks
:

#navigation{
width:150px;
height:30px;

}
#navigation ul
{
margin:0px;
padding:0px;
    }
#navigation ul li
{
display:inline;
height:30px;
float:right;
list-style:none;
margin-left:15px;
position:relative;
font-size:small;
font-family:Tahoma;

}



#navigation li a
{
     text-decoration:none;
     
}
     
#navigation li a:hover
{ }


#navigation li ul
{
margin:0px;
padding:0px;
display:none;
position:absolute;
left:0px;
top:20px;

}
#navigation li:hover ul
{
display:block;
width:160px;
}
#navigation li li
{
list-style:none;
display:list-item;
}
#navigation ul
{margin:0px; padding:0px;}
#navigation ul li
{
    display:inline; height:30px; float:left; list-style:none;
    top: 0px;
    left: -44px;
    width: 138px;
}
.menutd
{
    width: 150px;
    color: #FFFFFF;
}