Problema con Explorer

Hola amigos de la comunidad estoy haciendo un menu de navegacion usando css3 pero al parecer no es compatible con internet explorer version 9.8.7 y 6 mira aca le paso el codigo ahber si me peuden ayudar, gracias.

body {
background:rgba(255,255,0,.5);
filter:progid:DXImageTransform.Microsoft.gradient(startColorstr=#80FFFF00,endColorstr=#80FFFF00);
}

#nav {
width:800px;
height:50px;
border:1px solid black;
margin:0 auto;
}

#nav ul {
padding:0;
margin:0;
background:rgba(0,0,0,.;
filter:progid:DXImageTransform.Microsoft.gradient(startColorstr=#80FFFF00,endColorstr=#80FFFF00);
-webkit-opacity:.8;
-moz-opacity:.8;
opacity:.8;
filter:alpha(opacity=80);
height:50px;
-webkit-box-sizing:border-box;
-moz-box-sizing:border-box;
-ms-box-sizing:border-box;
box-sizing:border-box;
word-spacing: -4px;}

#nav ul li {
display:inline-block;
padding:0px;
margin:0;
width:200px;
height:50px;
background:#ccc;
-webkit-border-radius:20px 0px 20px 0px;
-moz-border-radius:20px 0px 20px 0px;
-ms-border-radius:20px 0px 20px 0px;
border-radius:20px 0px 20px 0px;
behavior: url(ie-css3.htc);
box-sizing:border-box;
text-align:center;
line-height:50px;
}

#nav ul a li {
color:rgba(0,0,0,.;
filter:progid:DXImageTransform.Microsoft.gradient(startColorstr=#80FFFF00,endColorstr=#80FFFF00);
-webkit-opacity:.8;
-moz-opacity:.8;
opacity:.8;
filter:alpha(opacity=80);
text-decoration:none;
font-family:Arial Narrow;
font-weight:bold;
font-size:17px;
-webkit-transition:1.5s ease 1.5s;
-moz-transition:1.5s ease 1.5s;
-ms-transition:1.5s ease 1.5s;
transition:1.5s ease 1.5s;
behavior: url(ie-css3.htc);
}



#nav ul a li:hover {

color:#ccc;
background:rgba(0,0,0,.;
filter:progid:DXImageTransform.Microsoft.gradient(startColorstr=#80FFFF00,endColorstr=#80FFFF00);
-webkit-transition:1.5s ease;
-moz-transition:1.5s ease;
-ms-transition:1.5s ease;
transition:1.5s ease;
behavior: url(ie-css3.htc);

-webkit-border-radius:0px 20px 0px 20px;
-moz-border-radius:0px 20px 0px 20px;
-ms-radius:0px 20px 0px 20px;
border-radius:0px 20px 0px 20px;
behavior: url(ie-css3.htc);