This bug has been reported at connect's IE beta feedback as bug 348575.
Firefox 2.x, Firefox 3, Opera 9.26, Opera 9.50, Safari 3.0.4, Safari 3.1, Seamonkey 1.x, Seamonkey 2.x, K-meleon 1.x, Galeon 2.0.4, Konqueror 3.5.8, Epiphany 2.22 all pass this test.
Credit must go to Batiste Bieler for discovering, reporting this bug and for providing a testcase on this precise bug.