It looks like Google was just teasing me with the traffic spike over the weekend, because it's all back to "normal" now. Does the Panda algo test a site? Throw some traffic at it and see what happens before lifting the penalty for real? Probably just a side effect of fluxing from other sites moving around... bummer! My ads are ALL far below the fold, I've got rel=canonical on all my attachment pages (pointing back to the parent), I've removed thin pages. Guess it's not good enough for the mighty Panda.