Lower PPC when driving AdSense traffic through AdWords?

Has anyone ever noticed something like this?

[ari11210]

Hello all,
One of the pages on my site gets ads for a high paying keyword. In January, these averaged over a dollar/click and in february averaged over $2/click. But, I wasnt getting much traffic to this page, only about 100 clicks/month. About a week ago, I decided to try and drive more traffic to this page using adwords and bought some related, but low priced keywords. Since buying these keywords, I have gotten a bit more traffic to this page, BUT at the same time, my PPC has dropped considerably. Now, this might be a coincidence, but I guess it is possible that google checks when traffic is being sent through adwords and lowers the PPC. Does anyone have any insight into this? Should I wait it out and see if my PPC goes back to what it used to be? With these lower PPCs it doesnt really pay to buy these ads anymore.
Any help would be appreciated,
Thanks

[doingthistoolong]

A lot of the higher priced keywords have fallen, I think this is the source of a lot of the concerns you see here. I still use adwords though, I see it as a "cost of business". A lot of people who come to my site end up bringing 100 more, so I still feel it's worth it.

But I am a bottom-sucker on Adwords, in the $.05 keywords space, which only shows up in search anyway.

[ari11210]

So, I should assume it is just a coincidence that my EPC has dropped dramatically since beginning to use AdWords to direct traffic to my AdSense ads?

Thanks