Now that's very disturbing!
I've noticed pretty steady drops in conversions in some of my AdWord campaigns over the last several months. Clicks to my ads, on the other hand, have increased.
Early this week I stopped showing my ads in Google's "content network" cause I was concerned I was getting a ton of bogus clicks.
Today I was looking over my AdWords stats and noticed I was being charged for several clicks on keywords which the stats also showed no impressions for. I'm just not clear on how an ad can get clicked on when it hasn't been shown.
I'm going to have to keep a very close eye on things this month.
Regards,
SF