CSS problem with IE7, theme alex_2_0

Hi all,

I'm having a serious CSS problem in IE7. It's not on all pages, just on the user pages of others. An example: when i log in to the website my current page is http://ikverdieneenjob.be/MYUSERNAME. When i go to another user page, http://ikverdieneenjob.be/OTHERUSERNAME the CSS is messed up.

Here are 2 screenshots:
CSS wrong: http://ikverdieneenjob.be/website-css-problem.jpg
CSS okay: http://ikverdieneenjob.be/website-no-problem.jpg

I have some special blocks (user relationship) displayed on the other user pages, but i allready disabled these to check.

In Firefox 3.6.8. i have no problem, only in IE7.

I use "margin: 0 auto;" to center my content and have a width of 950px.

Here's the most important part of my CSS file, i worked with the alex_2_0 template.

/* $Id: style.css,v 1.1.4.2 2008/01/13 23:47:31 Gurpartap Exp $ */

/* Main container styles */
* {
  margin: 0;
  padding: 0;
}

body {
font: normal 0.8em "helvetica", sans-serif;
line-height: 1.6em;
color: #666666;
background: url(img/top_bg.gif);
background-repeat: repeat-x;
}

/* TinyMCE specific rules */
body.mceContentBody {
   background: #FFF;
}

/* header span*/

#header {
  width:100%;
  height:175px;
}

#headerInner {
  position: relative;
  width: 950px;
  height:175px;
  margin: 0 auto;
}

/* logo, text logo, and slogan */

#siteName {
  font-family:"trebuchet ms", helvetica, sans-serif ;
  color: #fff;
  font-size: 44px;
  text-transform: lowercase;
  display: inline;
  line-height: 110px;
}

#siteSlogan {  
  font-family:"trebuchet ms", helvetica, sans-serif ;
  float:left;
  margin:33px 0 0 10px;
  color: #eee;
  font-size: 24px;
  white-space:nowrap;
  text-transform: lowercase;
}

#siteName a {
  color:#fff;
  text-decoration:none;
}

#siteName a:hover {
  color:#ddd;
  text-decoration:none;
}

#logo {
  float: left;
  margin:20px 0 0 0;
}

#logo img {
  float: left;
  border: 0;
}

#logowrapper {position: absolute;}
#logowrapper p{color:#fff;float:left;font-size:0.9em;height:40px;line-height:1.3;padding-left:5px;padding-top:32px;width:210px;}
#logowrapper p a{color:#fff;text-decoration:underline;}

/* navigation links */

#navigation{position:absolute;right:0;top:0px;}
#navigation li a{background:#fff url(img/menu.gif) no-repeat 0 100%;color:#2d373f;display:block;font-weight:700;margin:0 3px;padding:5px 0;text-align:center;width:90px;}
#navigation li.active a,#navigation li a:hover{color:#2b76af;padding-top:12px;text-decoration:none;}
#navigation li{float:left; list-style:none;}

/* main body layout */

#main {
  background: #fff;
}

#mainInner {
  position: relative;
  width: 950px;
  margin: 0 auto;
  padding-top: 1em;
height:50%;
}

/* 3 columns and primary content layout */
  
#primaryContent {
  position: relative;
  margin-right: 17em;
  margin-left: 0.2em;
}

#primaryContent h3 {
  margin:5px 0 5px 0;
border-color:#66CC66;
}
  
#secondaryContent{
position:relative;
width: 200px;
margin: 0em 0em 0em 0em;
color: #B9B9B9;
padding-bottom:150px;
float:right;
padding-left:20px;
}

#columns {
  position: relative;
  float: left;
  width: 100%;
  margin-right: -34em;
  margin-bottom:15px;
  padding-right: 2em;
  overflow:hidden;
  display:block;
}

#columns h2 {
  font-size:18px;
  margin:10px 0 5px 0;
}

/* begin sidebarLeft */

#sidebarLeft {
background: #66CC66;
}


#sidebarLeft .title {
  margin:0;
  padding: 0;
}

.sidebarLeft-content {
padding: 0 15px 0 15px;
text-align: justify;
}

#sidebarLeft span#topspan {
display: block;
height: 52px;
width: 200px;
margin: 0;
padding: 0;
background: #fff url(img/topik.png) no-repeat top left;
}

#sidebarLeft span#topspan img{
margin-top:10px;
text-align:left;
margin-left:0;
padding-left:2px;
}

#sidebarLeft span#bottomspan {
display: block;
width: 200px;
margin: 0;
background: #fff url(img/bottomik.png) no-repeat top left;
position:relative;
background:#009933;
text-align:center;
padding:5px 0 15px 0;
}

#sidebarLeft #bottomspan a {
color:#fff;
font-weight:bold;
}
  

#sidebarRight {
width: 200px;
background: #66CC66;
float: left;
margin: 4.7em 1em 0.5em 1em;
color: #B9B9B9;
}
  
#sidebarRight .title {
  margin:0;
  padding: 0;
}

#sidebarRight h3 {
  border:none;
}

.sidebarRight-content {
padding: 0 15px 0 15px;
text-align: justify;
}

Thanks for the help,

Greets,
Gunther