Post reply form off-center in Internet Explorer

[effex]

Hello everyone, I recently decided to switch over to Internet Explorer just to see how my 2.0 forum looks. I noticed that the Post reply screen's form isn't centered like on the other browsers. Does anyone know what could be causing this and which CSS elements should be looked into? I am using the Core theme. Thanks!

NOTE: Included a screen shot.

Update: While, I only changed the images and colors on the CSS file, I assumed that I might have accidentally changed something I shouldn't have. I went back and replaced the CSS file with the original one that comes with the forum and it still wasn't displaying properly. Is this a Internet Explorer bug with SMF 2.0's Core theme?