A line that has been cleared (i.e., clear: left) starts around (possibly just above) where it should be vertically, but the first line of the text wraps next to the float below which it should be cleared. The problem on this page occurs just below the four left-floating boxes next to each other.

the bug is actually caused by the delayed application of top-margins.

I believe this bug is also causing the problem on http://www.w3.org/Style/CSS/Test/current/sec5526b.htm where the second float is not quite clearing the first, and so is misplaced. This can cause major layout problems, so bumping up the severity.

This also causes problems on 5.5.25c and 5.5.25d (because it also effects the presentational HTML clear).

The problem is triggered by the margin on the floating element. (If I set the margin to 0, it is fine.) What you need to do is use the margin on the floating element but not the margin on the non-floating one. The best way to think about this may be as the spec says: increase the top margin on the element with clear until its top border edge is below the bottom margin edge of the floating element.

Setting all current Open Critical and Major to M3

per leger, assigning QA contacts to all open bugs without QA contacts according to list at http://bugzilla.mozilla.org/describecomponents.cgi?product=Browser

New test case for this bug: http://www.fas.harvard.edu/~dbaron/tests/nglayout/topmarg3

We now lay this page out properly. Look for the fix in tommorows build.

Verified fixed.

*** Bug 6731 has been marked as a duplicate of this bug. ***

??? Bug 6731 quite clearly has not been marked as a dup of this one.