Looks good in FF not in IE7

I cannot figure out what is happening with this page. I am editing a page that was created by someone else. I don't understand how come the right border graphic lines up perfectly with the header and footer in Firefox but not in IE7. I even tried making the spacer width smaller by a pixel but that just made both versions show the border a pixel too far to the left.

I think that I just need another pair of eyes. I have gotten myself frustrated so I am sure that the answer is right in front of me.

Thank you so much for your help!