Drop Down menu problem - IE 7

Hi All,

I have a delicate problem with my dropdown menu. I works fine in all browsers (Firefox, IE8, Safari, Netscape)but not in IE7.
The URL: http://www.acorno.se/karriar.html

I have tried to change measurement values, etc but nothing seem to give me a hint of what to do. I am rather new to CSS so I am very thankful for all help/support I could get.

CSS code:

@charset “UTF-8”;
/* CSS Document */

body {
margin:0px;
padding:0px;
height:100%;
background-color:#efeff0;

  }
  
 * {
margin: 0;
padding: 0;
height:100%;
} 

a, a:link, a:visited {
color:#000;
}

a:hover, a:active {
color:#666;
}

a.nav, a.nav:link, a.nav:visited {
text-align:center;
text-decoration:none;
font-family:Arial, Helvetica, sans-serif;
font-size:9px; color:#c0bbbb;
}

a.nav:hover {
color:#fff;
}
a.nav:active
{

color:#fff; 
}

p {
display:inline;
line-height:14px;

}

h3 {
font-family:Arial, Helvetica, sans-serif;
font-size:14px;
margin:0;
padding:0;
display:inline;
}

h4 {
font-family:Arial, Helvetica, sans-serif;
font-size:12px;
margin:0;
padding:0;
display:inline;
}

h5 {
font-family:Arial, Helvetica, sans-serif;
font-size:11px;
display:inline;
}

ul.inside {
list-style-position:inside;
}

a[name] {
margin-top: -100px;
position:absolute;
}

#header_wrap {
width:100%;
height:54px;
margin:0;
position:fixed;

/background-color:#306;/
}

#space-top {
height:120px;

}

#header_black {
background-color:#000;
width:100%;
height:10px;
}

#header_menubar_wrapper {
width:100%;
background-image:url(img/header_bg);
background-repeat:repeat-x;

}

/* MENU */

#menu {

width:760px;
margin:0px auto;
z-index:99;
padding-left:20px;

}

/* new */

#menu ul .item{
display:none;
background-color: #f0f8ff;
padding: 5px;
border-left:3px solid #000;
border-right:3px solid #000;
border-bottom: 0.1em solid #696969;

}

#menu ul:hover .item{
height:20px;
display:block;
background:#000;
padding:5px;
margin:0px;
padding-left:0px;
font-family:Arial, Helvetica, sans-serif;
font-size:10px;
font-style:normal;
line-height:20px;

}

#menu ul:hover .item a{
color:#c0bbbb;
text-decoration:none;

}

#menu ul:hover .item a:hover{
color:#fff;
}

#menu ul{
height:25px;
width:116px;
float:left;
margin:0px;
margin-top:20px;
/background:#b10000;/
list-style:none;
text-decoration:none;
font-family:Arial, Helvetica, sans-serif;
font-weight:bold;
font-size:12px;
color:#c0bbbb;
text-align:center;

}

/-------/

#menu ul .top a{
text-decoration:none;
color:#c0bbbb;

}

/* #menu ul:hover .top{
display:block;
background:#000;padding:1px;margin:1px;

}*/

#menu ul:hover .top a{
color:#fff;
text-decoration:none;
}

#menu ul:hover .top a:hover{
color:#fff}

/-----------/

#header_menubtn {
width:126px;
height:54px;
float:left;

}

#logo_holder{
width:700px;
margin:0px auto;
/background-color:#efeff0;
z-index:-2;
/

}

#logo {

float:right;
height:36px;
width:90px;
clear:both;
margin-top:10px;

}

#flash_wrap{
width:100%;
height:300px;

}

#bgimage_holder {
width:700px;
height:300px;
margin:0px auto;
z-index:-3;

    }

#pic_wrap{
width:100%;
height:300px;

}

#pic_holder {
height:300px;
width:700px;
margin:0px auto;

}

/* COPY */

#copy_wrap {
width:100%;
height:auto;
margin-top:30px;

    }

#copy_holder{
width:700px;
margin:0px auto;

}

#copy_headline_left{
float:left;
width:340px;
font-family:Verdana, Geneva, sans-serif;
font-size:11px;
display:block;
margin-bottom:5px;
}

#copy_headline_right{
float:right;
width:340px;
font-family:Verdana, Geneva, sans-serif;
font-size:11px;
display:block;
margin-bottom:5px;
}

#copy_column_left{
float:left;
width:340px;
font-family:Verdana, Geneva, sans-serif;
font-size:11px;
display:block;
}

#copy_column_right{
float:right;
width:340px;
font-family:Verdana, Geneva, sans-serif;
font-size:11px;
display:block;
}

#copy_column_divided {
float:left;
width:160px;

}

.clear {
clear:both;
height:1px;
}

.copyline_grey{
height:1px;
width:100%;
background-color:#a4a3a3;
margin-top:30px;
margin-bottom:30px;
}

#space {
height: 90px;

}

#footer_wrap {
width:100%;
height:75px;
position:fixed;
bottom:0;
background-color:#000;

}

#footer_greyline{
background-color:#d0d1d3;
height:3px;

}

#footer_menu_wrap {
width:100%;
height:65px;
background-image:url(img/footer_bg.jpg);
background-repeat:repeat-x;
}

#footer_menu_center_wrap {
width:700px;
margin:0px auto;

}

#footer_menu_center {
margin:0px auto;
width:500px;
height:30px;
padding-top:30px;
font-family:Verdana, Geneva, sans-serif;
font-size:9px;
color:#d0d1d3;
text-align:center;

}