Has anybody tried clearing cookies as I suggested?? If so I have yet to see any reports of if it works. In the past when issues happen, that seems to usually correct the problem (corrupt or invalid cookie). Chordie only provides a very small and limited space for Google Ad-Sense to place advertising, and sometimes they get greedy.... but we don't control their content, and if there is a problem from their end all we can really do is complain and let them fix it.
The other option is installing an Ad Blocking plug-in and not see any ads anywhere (which many have done with success). I clear all cookies on browser shut down always, so perhaps that is why I cannot duplicate your issue.
"what is this quintessence of dust?" - Shakespeare