of type boolean: When type has the value 'radio' or 'checkbox', this
represents the HTML checked attribute of the element.
coming from DOM 1 HTML Interface HTMLInputElement, defaultChecked attribute and coming from DOM 2 HTML Interface HTMLInputElement, defaultChecked attribute.
This bug has been reported at connect's IE beta feedback as bug 339083
Update: This bug has been FIXED in Internet Explorer 8 beta 2 (build 6001.18241) released on August 28th 2008. Otherwise, Internet Explorer 8 beta 2 PASSES this specific and particular testcase.