[web2py] my IE 6.0, the layout of four columns

[web2py_lover]

in my IE 6.0, the layout of
http://web2py.com/examples/default/index  shows ok
but mine (Current (1.99.4 stable))
http://127.0.0.1:8000/examples    shows not ok,

I think it is the problem of following, am I right?

I can't find the definition of four columns in any css file,
<div class="four columns">

                  <h3>Right Sidebar</h3>

                  <p></p>

 </div>