Internet Explorer 9 may not be as good as Microsoft claims

I've been doing some testing of the latest version of the IE 9 Platform and I don't seem to be getting the same types of numbers that Microsoft is claiming. Ignoring for the moment that it still doesn't pass Acid 3 (and probably won't from the comments that I've read), here are the results of an admittedly un-scientific test using sun spider 0.91. IE8 8700ms, Chrome 7.0.517.44 481ms, IE9 5267ms or IE9 is about 1.65 times as fast as IE8 and 10.9 times SLOWER than chrome 7. Now, Microsoft claims 3746, 262 and 216 respectively or basically that IE9 is 17 times faster than IE8 and slightly faster than Chrome 7. Clearly they are testing on a much faster maching that I'm running (a Pentium dual core 3.2ghz, with 8GB ram--windows experience index of 4.9) but that shouldn't cause this much skew in the data.

I'll be testing this further on a rather newer machine in the near future and will post the results of those test when they are completed. Anybody testing this for themselves, I'd love to hear your results (just post a comment)