Created attachment 51002 [details] Testcase The test here: http://samples.msdn.microsoft.com/ietestcenter/css3/selectors/notPseudoElement.htm fails.
I have a fix for this.
Created attachment 51084 [details] Patch
Comment on attachment 51084 [details] Patch > Property changes on: LayoutTests/fast/css/invalid-not-with-pseudo-element.html > ___________________________________________________________________ > Added: allow-tabs > + true Did you want this? r=me
Fixed in r56187.