Google've changed the way Campaign Summary and Ad Group Summary pages present statistics to give additional level of detail into your campaign performance. Previously, these pages divided statistics into two categories: search, which included Google and search partners, and the content network.

Now, Google show one set of statistics for Google and another set aggregating search partner performance. Search partners include AOL, Ask.com, and many other search sites around the web. You can view ad group or campaign performance at a summary level, or broken down by different combinations of Google, our search partners, and our content network. Additionally, separate Google and aggregate search partner statistics will soon be available in the Report Center.

More info: AdWords Help Center