buttons are not centering on the top navigation bar

Hi!

I need the buttons to center on the top navigation bar of this page:
http://www.orlando-web-hosting.net/
The left Home button is apparently being pushed to the right by one of the rules in our style sheet.
Here are section of rules that I believe control the buttons.

ul.dropdown{
position:relative;
list-style-type:none;
margin:0px;
}
ul.dropdown li{
width:115px;
text-align:center;
font-weight:700;
float:left;
}
ul.dropdown a:hover{
color:#FF00FF;
}
ul.dropdown li a{
height:20px;
text-align:center;
display:block;
font:bold 11px verdana, sans-serif;
color:blue;
border-right:1px solid #016494;
text-decoration:none;
padding:4px 6px;
}
ul.dropdown li.last a{
border-right:none;
}
ul.dropdown li.hover,ul.dropdown li:hover{
color:#000000;
position:relative;
}
ul.dropdown ul{
z-index:600;
visibility:hidden;
position:absolute;
top:100%;
left:-16px;
}
ul.dropdown ul li{
width:160px;
height:24px;
font-weight:400;
list-style-type:none;
background:#9FF;
color:#000;
border-bottom:1px solid;
float:none;
}
ul.dropdown ul li a{
border-right:none;
width:100%;
display:inline-block;
padding-top:4px;
color:blue;
}
ul.dropdown ul ul{
left:100%;
top:0;
}
ul.dropdown li:hover > ul{
visibility:visible;
}

Any specific suggestions as to what needs to be fixed would be appreciated.
Also, is there a way to remove the pipe to the right of the last button?
TIA