Advice About Compat Mode Needed

Hi All,

I’m working on a website for a client who is using this theme.

When using IE9 in compatibility mode, the menu gets hidden under the main picture and the white frame surrounding it. It does not do this in the normal IE9 mode.

Is there anyway to prevent this from happening if someone should view the site under these particular circumstances? I know it’s not a bug, but I want to try and avoid any hassles later.