Withouth seeing your website is quite dificult but have you tried to change your ad placement or colours recently? Sometimes it works...
Geez, looks like my stats this past few weeks. I am going to have to start working the corners downtown again.
Try playing with ad placement. Make sure you not allow just text ads. Graphical ads are more eye catching and people tend click more. BTW, you not suppose to show your stats as it is against AdSense TOS.