Aaz7 - 2:03 am on Sep 26, 2004 (gmt 0)

Aug 5th saw an algo tweak and a sudden drop of traffic for many. Aug 23-25 saw another algo tweak where sites that suffered on Aug 5th regained traffic but other sites lost 70%. Sept 22-23 seems to me similar to Aug 5th algo tweak where sites that suffered on Aug 23 regained but sites that got hammered on aug 5 were hammered again.

you've forgot to mention 2 onther drop-times: 30-31 of Aug, and 6-7 of Sep.