css in FF versus IE

Ik heb een website gemaakt met deze ccs classes:

}



input,
textarea,
select

{
background:#cccccc;
border: 1px solid #FF8C00;
color: #000000;
font-family: Tahoma;
font-size: 11px;
margin: 5px;
padding: 2px;
vertical-align: middle;
}





#c-col{
position: relative;
width: 800px;
border: 1px solid #000000;
background: #F5F5F5;
color: #333333;
padding: 0px;
z-index: 0;
}

#l-col{
position: relative;
width: 100px;
border: 0px solid #000000;
background: #D3D3D3;
color: #333333;
padding: 25px;
z-index: 13;
}

#navigation a
{
color: #696969;
background: #D3D3D3 url(left-tab.gif) left top no-repeat;
text-decoration: none;
padding-left: 10px

}

#navigation a span
{
background: url(right-tab.gif) right top no-repeat;
padding-right: 10px
}

#navigation a, #navigation a span
{
display: block;
float: left

}

/* Hide from IE5-Mac \*/
#navigation a, #navigation a span
{
float: none
}
/* End hide */

#navigation a:hover
{
color: #F5F5F5;
background: #D3D3D3 url(navlh.gif) left top no-repeat;
padding-left: 10px
}

#navigation a:hover span
{
background: url(navrh.gif) right top no-repeat;
padding-right: 10px
}

#navigation ul
{
list-style: none;
padding: 0;
margin: 0
}

#navigation li
{
float: left;
margin: 0;
}

#links {
width: 125px;
height: 700px;
float: left;
background: #D3D3D3;
color: #808080;
}

#rechts {
width: 125px;
height: 700px;
float: right;
background: #D3D3D3;
color: #808080;
}

#content {

height: 85%;

text-align: justify;
border-left: 0px solid #cccccc;
border-right: 0px solid #cccccc;
margin: 0px;
padding: 20px;

}

#bovenkant {
height: 15%;
width: 100%;
border-bottom: 0px solid grey;
float: center;

}

Maar dit werkt in IE prima, in FF wordt het nogal lelijk...

weet iemand wat ik verkeerd gebruik in deze css classes zodat FF 'm verkeerd leest?

thnx

ArendJan