Earlier quoted context omitted.
Same reply here as below: "Sorry, that's not an excuse. IE 8 comes with a "compatibility mode" feature where any site can choose to use the IE 6 rendering engine by setting headers or meta tags appropriately."
Nope.. that compatibility mode is for IE7 , not IE6. (And my understanding is that it's not even a perfect emulation of IE7.) Microsoft's official recommendation for developers is to install IE6 in a VM if you need to test compatibility. It's that bad.
MultipleIE doesn't work on Windows 7, which is what I'm using.