incrediBILL - 11:00 pm on Jun 12, 2013 (gmt 0)
I've seen ads disabled on a per page basis and an easy way to test that used to be putting 5 ads on a page, most if not all would quit working until you removed a few.
Another way I know works on a per page basis is content with blacklisted words on the page as the ads will stop until the page content is corrected. Another problem I solved on a site by automatically substituting stop words found anywhere on the page before it's displayed. I never change the original content, just the output, so I'm filtering, not censoring as pages I've removed AdSense from revert back to original unfiltered text. :)