true_INFP - 10:49 am on Jul 27, 2010 (gmt 0)
I've run AdWords campaigns before on the AdSense network and a $0.25 bid may only cost me $0.05 on some sites, so you know you're being smart priced to the extreme when a click is only worth $0.05 on your site.
That could have been caused by different levels of competition on the sites. Your maximum bid is reached only if there are other advertisers in the auction outbidding you for the ad unit spot.
I don't see any way to conclude with your level of certainty that one of the sites was being Smart Priced.