Play with the position and style of that ad (if you don't want to ad more..)
So put it in the middle of the article, under the article, etc.. Measure what works best.
Even better would be to have it randomly change color (you can set this when you create the adsense ad) though that could be annoying..
Or simply randomly change the format of the ad: small rectangle, big rectangle, banner, etc.. you will need to code this yourself, but it should help with banner blindness.
I've had a lot of luck with Adsense in the left column, with similar font and color to the primary content. Click-throughs were twice what they were with the same ad in the right column.
