hasLayout VS new block formatting context

Question

Sounds like hasLayout making the same function as "new block formatting context" does. I have known exactly what "new block formatting context" works, but I am not clear about what's hasLayout in deep and what's his job.
What I know about "hasLayout" is:

1: hasLayout flat was used to trigger css properties so the page would be rendered correctly.

Q: What is the "css properties" referenced here?

2: If hasLayout set to true-element is a box that is responsible for rendering itself.

Q: Is it the same with "new block formatting context"?

3: the following properties give element layout:

position:absolute;
float;
display:inline-block;
width:not auto;
height:not auto;
zoom;
writting-mode;

Q: If a element inside our shrink wrapped friends has "layout" and the width is not restrained our shrink wrap will fail, why?

Here is a link, saying something about hasLayout, maybe it will help me to explain my problem.

More details:

html

 <ul class="ofArrowLinks">
     <li class="ofOpen">
    <a href="#">
      <span>Link01</span>
    </a>
     </li>
     <li class="ofOpen">
     <a href="#">
    <span>Link02</span>
     </a>
      </li>
     <li class="ofOpen">
    <a href="#">
          <span>Link03</span>
    </a>
 </li>
 </ul>

css

   .ofArrowLinks li{
    float:left;
    font-size:12px;
    line-height:2.7;
}
.ofArrowLinks a{
    display: block;
    padding: 0 0 0 10px;
    text-decoration:none;
    height:41px;

}
.ofArrowLinks .ofOpen a{
    background: url(../../common/images/tab04a.gif) no-repeat scroll left top transparent;
    cursor: default;
}
.ofArrowLinks span{
    font-weight:bold;
    display: block;
    height:30px;
    padding: 0 18px 0 0;
}
.ofArrowLinks .ofOpen span{
    background: url(../../common/images/tab04b.gif) no-repeat scroll right top transparent;
    color: #FFFFFF;
}

IN IE6:

The reason is that i have set a height to and that are using the property displayed:block, so the width of them is to auto, never shrink wrap the content.

in other browser, what i expect to see:

This is the hasLayout's fault!!Nobody can help?? so sad.....