Internet Explorer screwing up my page

When I view this page in Internet Explorer, my sidebar seems to have moved to underneath the ‘Leave a reply’ form – only in IE – I am using the I-feel-dirty theme and I have diffed many, many of the files and cannot figure out where I am going wrong – do you mind taking a peek at the page and seeing if anything jumps out?

https://www.thingsinyourhead.com/?p=341#comments

Thanks so much