Acrill - 12:42 am on Jun 16, 2010 (gmt 0)
When running Content Network ads you should be choosing different keywords than you would use for Google Search ads.
Think of it like this: With Search ads the keywords you select should match search queries that users enter into Google.
With Content Network ads, the keywords you select should reflect the theme of pages where you want your ads to show. They should generally be broader than the keywords you would use for Search ads.