I am having the same issue. The theme looks great in IE9 but is distorted in IE7 & IE8.
You can view the issue by going to developer options and selecting IE9 Compatability Mode. One of the sites I have created using this theme is http://www.d2dpetsitting.com.
I have a feeling this is a float or overflow issue. I found this link which might help: http://net.tutsplus.com/tutorials/html-css-techniques/9-most-common-ie-bugs-and-how-to-fix-them/
I will mess with it some more to try and find the fix, but if someone beats me to it, PLEASE SHARE.
Thanks so much! Great theme by the way!