I ran a report this morning like I alwasy do and one of my sites showed nothing. I did not rank in the top 140 pages for any terms that I had. I ran the report again a few minutes ago and everything that I ranked for before was gone. The strange thing is that I ranked for 39 different words that I never did before. I noticed a trend and checked it out. This was done with only 6 pages and the cache showed that each of those pages had PSA's on them.