Webpage isn't looking the same in Internet Explorer as it does in Firefox?

I am currently building a new personal blog. The webpage looks fine in Firefox and Safari, but when i test it out on an Internet Explorer, the font is MUCH larger than it’s supposed to be. Why is this? How can i fix it?
I’m currently using the latest version of Wordpress with the DePo Skinny theme (customized a bit). My site is at http://www.kvnkm.com/
Thank you in advance.
Kevin