Does Google reduce adsense payout for adwords driven traffic?

Does Google reduce adsense payout for adwords driven traffic?
I have a site that I’m getting traffic to from adwords, but i also have adsense on the site, i greatly increased my adwords spending and I noticed a big decrease in adsense payout from traffic generated by adwords. Clicks went way up but pay dropped by 50%.
Does google have some kind of mecanism here to avoid people doing arbitrage (even on real sites – not made for adsense sites)?

Original post by Buckenmeyer