Logo display location in IE8 dramatically reduces width of main site

I would like to display a company logo that is about 500px x 100px (W x H). In Firefox 3, the logo displays above the left column of the menu list and the left portion of the main content box. Perfect. But, in IE8, the logo displays only to the left of the menu list, not really above it, at least not enough. That causes the main portion of the site to be reduced to a size that is useless, since most of the content is not being displayed. For example, I can access the Themes page in Admin, but all I see are the left-most images displaying the thumbnail of the themes' pages. I am not able to select "configure" since it is not even visible.

It displays in Chrome like it does in Firefox. Good. (I don't have any other browsers installed.)

Just wondering if you could look into this, since I really like the theme, which fits well with the company's business.

Thanks in advance.