I don't know that skin but I am familiar with the problem. It comes from IE deciding there is a different way to interpret certain css elements than the way the standard was written (and how most other browsers interpret them). I forget exactly. Something about whether or not padding and margins are inside or outside the box being padded or margined.

Lets fix it. Find this in your 01_style0101.css file:

/*The container - edit "230" to your desired width for the sidebar (lines 55, 58, 62)*/
#container{
	width: 100%;
	float: left;
	margin-right: -230px;
}
#content{
	margin-right: 230px;
	padding: 25px 0;
}
#sidebar{
	width: 230px;
	float: right;
	padding: 25px 0;
	text-align: left;
}

I should test some of this first but hey - it's your blog! First start by shrinking the content padding and sidebar padding to 10px and see if you get a groove out of it. Second, it might be more effective to change the sidebar width to, oh I dunno - 180px (230 minus a pair of 25 paddings). Just to see which tweak makes it wiggle like it should. Once you get it to wiggle the way you want then you can dial in the numbers to use the screen the way you want. For example maybe padding at 22px will work but not at 23px?

Hmmm.... You might have to tweak both the padding and the width of the sidebar, but don't make all the 230s be the same number - just the width of the sidebar.

That worked. Thank you very much!