Hi Immortum!

I don't know who made your Custom Content Box HTML, but wow... it really needs to be fixed. Funny thing though is it isn't causing the trouble you're having.

I can't tell you how long I took trying to figure out why IE was messing up the page. I was about to tear my eyes out when I found it. I can't tell if you added it manually or if it's from the Site Style for Content Boxes, but get rid of the drop shadow! This line in the CSS needs to be removed (the main problem is the part in red):

.ContentBox { margin-bottom: 5px; border: solid 1px #d1cccc;  filter:progid:DXImageTransform.Microsoft.dropshadow(OffX=2, OffY=2, Color='black', Positive='true'); -moz-box-shadow: 2px 2px black; -webkit-box-shadow: 1px 1px 2px #000;}

If you didn't add it manually, try going to Control Panel > Site Style > Content Boxes > Border > Border Drop Shadows (Uncheck this!).... but I tried turning this on and it didn't cause the same problem on one of my test sites. So I don't really know if that was the problem. I looked, but it's late, and I couldn't find any where else in the Site Style where it had an option for a drop shadow.

Anyway, here is your Custom Content Box HTML cleaned up a little (Control Panel > Custom Code > Content Boxes: Left Side, Center, Right Side)

<table class="ContentBox" width="100%" cellpadding="0" cellspacing="0">
 <tr>
  <td class="ContentBoxTitle">$block[title]</td>
 </tr>
 <tr>
  <td class="ContentBoxBody">$block[content]</td>
 </tr>
</table>
<br>