The following layout test are flaky on snowleopard debug fast/frames/calculate-order.html fast/frames/valid.html
fast/frames/valid.html is the only one still failing, but it's always failing now on Leopard and Snow Leopard (debug not relevant). Marking as non-flaky.
Rebaselined on SL in http://trac.webkit.org/changeset/123403 : The only difference from Lion was the scrollbars.