plasma - 9:55 am on Mar 18, 2007 (gmt 0)
10 days ago, I rebuilt my website. The content stayed the same, only the code changed. I moved from JS popup menus to CSS ones.
Immediately our rankings fell from mostly #1 to almost void.
When I compared the new and old code I realized, that in the past the navigation was at the bottom of the code, now it was at the top.
Yesterday I changed it so it appears at the bottom of the code and get's displayed at the top via position:absolute. During the night we were - like always - fully crawled, and our rankings completely recovered.