1script - 5:47 pm on Apr 9, 2010 (gmt 0)
I don't think this setting matters much. I don't have it on my affected sites.
"Your site has been assigned special crawl rate settings. You will not be able to change the crawl rate."
I also don't see any improvement in Google traffic. However, I have an observation: the set of keywords that my sites do still rank for has shifted since March 15th (the day the traffic died). Even though a few keywords are still going strong, even after March 15th, vast majority on those that bring Google traffic have completely changed. The set of the most ranked keywords has been stable for at least 1 year before March 15th, 2010. It now looks like it's been "stirred up" and the sites have to be re-ranked from the ground up on all of those keywords. Is it any similar to what you are seeing among your ranking keywords?