If font size and background image position are set on the <body>, IE positions the background as if font size hasn't been set. If you view this page in IE6 or IE7 the vertical line produced by the background image is half the distance from the left edge that it should be.
The CSS for this page is as follows:
body {
background: #FFF url(right-shadow.gif) repeat-y 10em;
font-size: 2em;
}
This affects IE6 and IE7. Funnily enough it doesn't affect IE5.