IE8 bug - The horizontal scrollbar is added instead of subtracted from the min- or max-height


"Any space taken up by the scrollbars should be taken out of (subtracted from the dimensions of) the containing block formed by the element with the scrollbars."
Quote from the W3C CSS 2.1 Specification, Section 11.1.1 Overflow: the 'overflow' property

Both boxes should be exactly the same height (of 200px).