[don't tick zero ticks, be strict in key argument
John Meacham <john@repetae.net>**20060411014507] hunk ./Stats.hs 175
-mticks n k = n `seq` mticks' n (toAtom k)
+mticks 0 _ = return ()
+mticks n k = let k' = toAtom k in k' `seq` n `seq` mticks' n k'