Adsense Penalty?

Yukon, I'm talking about what's on the "sites" page in the adsense perfomance reports. The coverage, which is supposed to indicate the amount of ads returned by google for ad requests, says 0.00%., which I take to mean that Google can't (or won't) find ads related to my content.

This site is not new; it's a couple of years old. I never got a lot of clicks, but I did get a few high-paying ones a few times or more a week. (It's medical related.) Then when Panda hit in April, my rankings dropped, and my few adsense clicks became even fewer and farther between.

Then one day about four weeks ago, somebody clicked on four ads at once, or right together. That had never happened before. But I have not had one click register since then; not one. And today I notice that my coverage is 0.00%.

I have indeed made changes to my site over the past few weeks...better organization and more content. Shouldn't Google like that???

When I look at my site, however, I can see ads, and they are targeted. So, I'm really confused as to what's going on here.

There's never been any activity on my part to put me on google's radar for suspicious activity. And I'm really "small potatoes" in terms of backlinks and traffic, so why another person would choose my site to bomb with four measly clicks, I don't know. But like I said, I haven't had one click since then, although my traffic has been doing fine for this site. I would say with my recent added content, my traffic is almost back to where it was pre-panda when I would get some clicks every week.

If it weren't for that 0.00% coverage thing that doesn't look at all encouraging, I would just be waiting this out till I get more traffic.