"When OBJECT elements are treated as images natively, the
useMap attribute of an OBJECT element allows a MAP
element, specified elsewhere in the document, to apply to the
given image. Note that this applies only to MAP elements defined
outside the scope of the current OBJECT and its fallback
coming from Internet Explorer 8 beta 1 white paper "HTML Improvements and ACID2" PDF document, March 5th 2008, 558KB from Microsoft, downloadable at http://code.msdn.microsoft.com/ie8whitepapers/Release/ProjectReleases.aspx?ReleaseId=572
Internet Explorer 7, Firefox 18.104.22.168, Firefox 3, Opera 9.27, Opera 9.50, Seamonkey 1.x, Seamonkey 2.x, NS 7.2, K-meleon 1.x, Galeon 2.0.4, Epiphany 2.22 all pass this test.
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.