netmeg - 7:44 pm on Feb 22, 2013 (gmt 0) [edited by: netmeg at 7:46 pm (utc) on Feb 22, 2013]
Well you could ask support if they see something weird going on. Supposedly what they're there for.
I had a bit of a crash on the 15th, but it recovered by the 18th.
I guess I'd start looking page by page if I were you. And also maybe look for changes in my traffic - coming from a different place, or more mobile (or less) than usual, or...?
You might also check to see if there's any big change in your unmatched ad requests.
[edited by: netmeg at 7:46 pm (utc) on Feb 22, 2013]