So what is the solution here? I'm sure its not that I should be running IE9 :-)
I'm experiencing the same problem rendering the site on Chrome in Windows 7. I tried running through the ClearType tuning thing - with no success.
However, it appears that Chrome on Windows is the problem here, as it also renders fine in Windows Firefox. Chrome and Firefox in Ubuntu works fine as well.
Here is a Windows 7 comparison of Chrome vs Firefox rendering: