Unfortunately, this causes a problem with the LJ Xcolibur skin.
Since http://stat.livejournal.com/xc/basic.css sets padding to 0 for the body element, the top margin of the
Padding changes things because it stops the margins collapsing together.
I suggest setting the default padding for to 1px or some other small value in basic.css, or leave any statement out so the browser's default values can apply.
(First posted in support.)