[Louis]

Found this:

Originally Posted by Google Adsense Help

Why don't my channel reports add up to my aggregate report?

Even if all of your pages are tracked using channels, your aggregate reports may show more clicks and impressions than your channel reports for a variety of reasons. The most common reason is that your pages have been shown in a frame. Occasionally, traffic programs or sites like Google Image Search use frames to display pages. When clicks occur on a framed page, they won't appear in your channel reports.

Please be assured that while some statistics may not appear in your channels, all clicks and impressions are being recorded correctly in your aggregate reports.