Ok, i've setup a site a week ago. Competitive niche, 22k exactly searches/month. I got it to #17 in google. Yesterday the site disappeard, it wasn't found in Top 1000 anymore. But the site was not deindexed. I checked it with: site:mydomain.com. The last cache date was 7.7.2011, so the ranking drop had nothing to do with on page factors. But the permalink to the article was still found at #90 for my keyword. I checked my offpage factors and i could see that i have to much anchors with my main keyword in it - around 90%. Today i did some backlinks again with another anchor text in it. Now it is #18 again. Did it ever happen to you that a site disappears for one day and comes back to the same spot again 24 hours later?