i have a problem in my coding which was working fine with firefox older version,when i updated to firefox 3.6 my vertical menu's first list is bigger then the other list... here is my css code...

#verti 
{
float:bottom;
width:300px;
margin-top:50px;
position:relative;
}

#verti ul li
{
position:relative;  
list-style:none;
} 

#verti ul
{
padding:0;
margin:0;
}

#verti li
{
height:2m;
width:9em;
background:#38ACEC;
margin-bottom:9px;
position:relative;
top:170px;
-moz-border-radius:80px;
border-radius:80px;
text-align:center;
}