Sorry for the delay...to get all the boxes into and equal height and also add a nice dashed border, just update the stylesheet_list_columns.css with the following:

Code:
/* contents */
div.centerBoxContentsProductsCols{
	margin: 5px;
    	padding: 5px;
	background-color:#FFFFCC;
	border:4px;
	text-align:center;
	height:290px;
	border-style:dashed;
}
I haven't checked it out of FF but it looks fine on IE6.