A while back when IE9 came out, the version of Cufon that was current at the time had a major issue w/ IE9. They released a new version right after to fix the problem. In short, make sure you are using the most recent version of Cufon.
Sorry for such a delayed response here. I struggled with it for a while after posting this and also stumbled upon the most recent version of cufon which fixed my problem… I used a combination of the new library and
I dont think the second part is 100% necessary but it helps eliminate some of the quirks between IE8 and IE9