not appearing right in IE

hello all,

learner to css here. inherited this site and have made edits.

When I send it to the client it appears funny in IE. can anyone diagnose what the error is my suspucions are that it may be the fact that i changed the previous version to have a position:relative #container.

is this having an adverse effect on the nested elements inside i.e.
#container
#content
#TextContainer
#logonav
#navigation
.maintext

to start;
1. there seems to be approx 5px extra on the right side of the conatiner div.
2. the height:797px isn't being read.

http://www.fuse.ie/website.jpg

CSS -
#container {
position: relative;
background-image: url(images/background.jpg);
background-repeat: no-repeat;
height: 480px;
width: 797px;
}

#logonav {
background-image: url(images/logo.gif);
clear: left;
float: left;
height: 344px;
width: 201px;
margin-left: 26px;
}

#navigation {
float: right;
margin-top: 223px;
margin-right: 16px;
width: 180px;
text-align: right;
}

#aboutus {
float: right;
margin-bottom: 14px;
}

#howtoapply{
float: right;
margin-bottom: 14px;
display: block;
}

#contact { float: right;

}

.arrow {
background-image: url(images/arrow.gif);
background-repeat: no-repeat;
display: inline;
}

.complaintlink {
font-size: 14px;

}

#content {
position: relative;
background-image: url(images/contentarea.jpg);
float: right;
height: 206px;
width: 540px;
margin-right: 30px;
margin-top:138px;
}

#TextContainer {
position: absolute;
top: 20px;
height: 185px;
width: 520px;
overflow: auto;
}

#TextContainerContact {
position: absolute;
top: 20px;
height: 185px;
width: 540px;
/*overflow: auto;*/
}

.maintext {
font-family: Verdana, Arial, Helvetica, sans-serif, Tahoma;
font-size: 11px;
color: #666666;
text-align: left;
top: 0px;
padding-left: 20px;
padding-right: 20px;
/*overflow:auto;*/
}

.heading {
font-family: Helvetica, Verdana, Arial, sans-serif, Tahoma;
font-size: 50px;
font-style: bold;
color: #66cc33;
top: 0px;
text-align: left;

}

#contentlower {
background-image: url(images/contentarea-lower.jpg);
float: right;
height: 24px;
width: 612px;
margin-right: 30px;
margin-top:0px;
}

#footer {
background-image: url(images/footer.gif);
float: right;
height: 61px;
width: 741px;
margin-top: 39px;
margin-right: 30px;
}

#displaybox {
position:absolute;
filter: alpha(opacity=85); /*older IE*/
filter:progid:DXImageTransform.Microsoft.Alpha(opacity=85); /* IE */
-moz-opacity: .85; /*older Mozilla*/
-khtml-opacity: 0.85; /*older Safari*/
opacity: 0.85; /*supported by current Mozilla, Safari, and Opera*/
position:relative;
top:30px;
left:25px;
width:535px;
height:420px;
padding:0px;
margin:0px;
background-image: url(images/navigation/overlay.gif);
background-repeat: no-repeat;

}

.maintextpopup{
font-family: Verdana, Arial, Helvetica, sans-serif, Tahoma;
font-size: 11px;
color: #666666;
text-align: left;
padding-left: 50px;
margin-top:0px;
width:420px;
padding:8px;
}

#close {
position:absolute;
top: 18px;
left: 512px;
height: 18px;
width: 18px;
padding: 0;
margin-right: 5px;
color: #666666;

}

.popuptext {
text-align: left;
height: 410px;
width: 600px;
}

#iframepad {
position:absolute;
padding-top:20px;
margin-left:8px;
}

.heading {
font-family: Verdana, Arial, Helvetica, sans-serif, Tahoma;
font-size: 16px;
font-style: bold;
color: #66cc33;
top: 0px;
text-align: left;
padding-bottom: 3px;

}

.footertext {
font-family: Verdana, Arial, Helvetica, sans-serif, Tahoma;
color: #FFFFFF;
padding: 14px;
text-align: center;
font-size: 11px;
}

/* legal note in the top right corner. absolute posiitioned outside in the container */

#disclaimer {
position:absolute;
width:50px;
height:20px;
z-index:4;
right: 30px;
top: 15px;
font-family: Verdana, Arial, Helvetica, sans-serif, Tahoma;
font-size: 10px;
font-weight: bold;
color: #666666;
}

#disclaimer a:link {
color:#666666;
text-decoration: none;
padding:0px;
}

#disclaimer a:visited
{
color:#555555;
text-decoration: none;
padding:0px;
}

#disclaimer a:hover {
color:#222222;
padding:0px;
}

a:link {
color:#66CC33;
text-decoration: none;
padding:0px;
}

a:visited
{
color:#66CC33;
text-decoration: none;
padding:0px;
}

a:hover {
color:#666666;
padding:0px;
}