I will suggest a large rectangle in the middle and referrals are not good. And I think red color will be better for title. As black and red is deadly combination. If your ctr is less than 7% try red color. If it near about or greater don't change anything just the big rectangle in the mid section.
Not very Good blending Remember ! Ads shouldnt look like ads if you want to get good CTR. I am not big fan of Blue Title of your ads.
should not use that blue color for the ads... blend it with the same color as the link in the rest of the page. like adsense_girl said, an ads should not look like an ads. ppl will not click..