Explorer trouble

Your HTML validation shows:
Sorry, I am unable to validate this document because on line 8 it contained one or more bytes that I cannot interpret as utf-8 (in other words, the bytes found are not valid values in the specified Character Encoding). Please check both the content of the file and the character encoding indication.
Your source code shows:

/***********************************************
* Disable Text Selection script- � Dynamic Drive DHTML code library (www.dynamicdrive.com)
* This notice MUST stay intact for legal use
* Visit Dynamic Drive at http://www.dynamicdrive.com/ for full source code
***********************************************/

and that is not valid HTML.

You’ve got to check your 41 HTML validation errors … e.g.
extra </li> in menu

<div id="menu">
<ul>
<li><a href="http://dhini.nl" alt="Home">Blog</a></li>
<li><a href="http://www.dhini.nl/overmij/overmij.php" title="Overmij">Dhinilicious</a></li>
<li><a href="http://www.dhini.nl/pixels/pixels.php" title="Pixels">Pixels</a></li>
<li><a href="http://www.dhini.nl/resources/resources.php" title="Resources/Site">WWW</a></li>
<strong></li></strong>
<li class="page_item page-item-615"><a href="http://dhini.nl/contact/" title="Contact">Contact</a></li>
</ul>
</div>

– missing start <li> tag throughout sidebar

<div id="left">
<ul>
<h2>Laatste post</h2>
<ul>

Plus just mixed up codes and tags you need to clean up like

<h2>Online</h2>
<ul><li>
 <script language="JavaScript" type="text/javascript" src="http://www.wieonline.nl/wie/wie.php?user=dhinivh" title="Wie is online?"></script>

<div id="eXTReMe">

Just not right