Created attachment 217536 [details] Test-case As per the CSS2.1 painting order, the floats are painted after normal flow contents, but before any positioned content in the same block formatting context as them (e.g. positioned elements paint on top of floats, too). However, when content with overlapping floats and positioned elements is flowed in regions, the floats get painted on top of the positioned elements. In attached file, you should see a green square (relatively positioned div), but WebKit shows a red square (the float). Possibly related to bug 124346.
After playing a bit with the test I've concluded the bug does't reproduce. Closing. - the green text is correctly positioned below the red square, offseted to the left with 100px - if I change left: -100px to top: -100px, the green square is painted on top, as expected. - using background-color instead of color has the same effect