deadsea - 11:53 pm on Nov 24, 2012 (gmt 0)
It seems likely that the algorithm is counting affiliate links as ads when it can. Your site may using affiliate links in a way that allows them to be detected when maybe your competitors are not.
From what I can gather they also don't want webmasters to push ads below the fold with white space. In other words, there must be more content above the fold than ads above the fold.
So move the following down in the page if possible: Ads, third party links, forms, whitespace.
And move up: text, images, flash.