ncsuk - 2:47 pm on Jun 18, 2003 (gmt 0)

Have you changed content recently, got new links, changed page structure etc etc.

There are massive amounts of variables that can change the way things are ranked, you could of inadvertantly deleted something that was holding a lot of weight for your site or added something that diluted the quality of something else.

Everything is relational and without me going to your site and spending hours analysing it I will not be able to tell you. Of course because the update is happening at the moment it could just be that your competitors have all done something and blitzed your listings.

It is all relational, see if you can find your site in the serps anywhere next time it happens, usually if you drop out you will find yourself on a page but it maybe wayyyy down the listings.