Posts are not displaying correctly in IE8

I just realized today that my WP blog (royalbouquetflorist.com) is not displaying correctly in IE8 & don’t know what is wrong. I don’t know how long this has been this way, and I really want to get this fixed ASAP. The site displays correctly in FireFox.

The specific problem in IE8 is that the individual posts are not displaying correctly. When you look at the site in IE8, the entire right side of my site underneath the header is blank. This is where the posts should be displaying. Instead, the posts are displaying at the bottom of the left sidebar, albeit they are truncated.

Can anyone help me figure out what is wrong? Again, this WP site displays corrected in FireFox. The site is: http://royalbouquetflorist.com

Thank you.