As the debugging tool of IETester is quite clumsy and limited, we can debug issues with IE6 directly in the shell of IE8. The only requirement is that we have Internet Explorer Developer Toolbar installed on our machine. Here we go:
1. All versions of IE prior to 8 trigger quirks mode despite of the DTD you are using if the XML prolog is added above it, so add it *:
<?xml?> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
2. Open IE Deveoper Toolbar and switch the rendering engine from IE8 to IE7 in order to trigger quirks mode via XML prolog.
3. Now your IE8 will behave exactly like IE6 with all its quirky stuff and you are ready to start fighting the hell out of it.
* Instead of adding the XML prolog, you can also switch the document mode from IE8 to Quirks Mode using IE Developer Toolbar.