trakkerguy - 7:33 am on Sep 7, 2011 (gmt 0)
Check your logs, you'll probably find a manual visit from a Google IP address. In which case you've been manually penalised - welcome to the club.
My thoughts exactly.
G has really stepped up the manual penalties lately. Usually -50. If really flagrant abuse, de-index.
Sounds like -50 for you, so at least there's a chance that you can come back. Re-consideration request might work.