Now if they had a test for web sites being in conformance...
Oh wait, there is IE6
A browser test that tripped up Microsoft and helped pull the company into greater compliance with web standards has itself been updated for the changing web. Acid3 has been modified so as not to fail browsers which implement certain APIs that are finding more widespread use online. Ian Hickson, W3C HTML spec editor, wrote in …
Im not sure what is wrong with your setup but the same IE9 64bit on Windows 7 setup scores 100/100 every time following the changes to the test. I am aware that there is more tested than just the score, but it's not only IE that isn't perfect in that regard, Firefox 7 on my machine is still having a couple of speed and no of attempt issues reported when clicking on the A in Acid.
First time I've run Acid 3 in months. Funny, but I saw that message on one run using the Comodo browser (Webkit based) - a second run had it appear for a split second and then it disappeared. Other browsers sometimes show it momentarily.
All the browsers I tested* got 100%, including IE9 (and I tested the latest versions of FF, Comodo, Chrome, Safari and Opera.
*except Lynx - :)
Chrome was passing but the recent update 14.0.835.186 fails, despite scoring 100/100 because it displays a message that should not be seen, the same goes for FF 6.0.2. IE9 is missing the text shadow. Opera is the only one out of these browsers to pass fully.