Given the following code, why does MSIE let the INPUT tag "shine through" the DIV? More importantly, is there a workaround?

Just to be clear, what I want is a SELECT that is hidden behind an absolutely-positioned DIV in MSIE Windows.

<select style="position: absolute; top: 100; left: 100; z-index: 0;">
  <option> Bobo</option>
  <option selected> Mookie</option>
</select>

<div style="position: absolute;
            top: 50; left: 50;
            width: 100; height: 100;
            background-color: #cccccc;
            z-index: 100;">
</div>