Ok, this is the correct update to the original one I posted.
The two commented lines are the changes compared to the previous one.
I've tested what I could in terms of content with IE, Firefox, Netscape, Seamonkey and Opera.
Code:
.center_column {
position:relative;
float:left; /* float left, default is top */
width:595px;
margin:0 0 0 0; /* remove the top margin */
padding:0 0 0 10px;
border-left:1px solid #999999;
}
