incrediBILL - 2:20 am on Mar 22, 2012 (gmt 0)

And people wonder why some of us chronically check our stats...

We don't wonder, we know OCD when we see it. :)

Doesn't matter how many times you check your stats, when they close your account it gets closed.

However, I seriously doubt that 2 incidents of Bing referrals is to blame, unless they can be tied directly to IPs that would tend to generate false clicks. I get more worrisome traffic from Google itself than anywhere else but you can't trust the referrer, it's just text, and it doesn't conclusively mean anything except the referrer field was filled in by someone/thing that visited the site.

The only thing you can rely upon 99.9999% of the time is the actual IP address which itself could be forged, just not easily. Forged addresses cannot connect to anything like AdSense as the forged IP address bounces elsewhere when the data is returned, not to the sender.The only variation on this theme is a proxy IP which isn't exactly forged but a private proxy can conceal the source of the original IP.

Where I would be looking, assuming the OP can still login to the AdSense account, is if there are any sources clicks outside of your domain generating clicks.