Actually this is an IE bug, which can't handle fixed positioning, not the other way around.. Here is an example of how fixed positioning is used:
http://www.jazzgeveltje.nl/It fixates the navigational menu and lamps.
So I guess you want to display the footer at the bottom You would have to do something like this:
#footer {
width:100%
margin:0;
clear: both;
border-top:2px solid #2b2b2b;
width:100%;
height:30px;
font-size:11px;
color:#666;
letter-spacing:3px;
}
You might want to adjust margin-top.