denisl - 3:13 pm on Apr 14, 2011 (gmt 0)
"Checking my "Your site on the web > search queries" looks like someone blasted the page with a shotgun."
I wouldn't take too much notice of that. All my sites are showing impressions and click down around 40% that day but traffic wise they have either stayed the same or shown a slight improvement.
I think G must have been too busy to capture the data that day