At this point, no one really fully understands the issue behind those warnings. An advertising policy guideline on Inflating Ad Clicks or Impressions was hyperlinked to by one AdWords helper. Then a Google representative, AdWordsPro, said that this was the correct answer to such a warning.
Don't promote inflating ad clicks or impressions.
Advertising is not permitted for the promotion of inflating clicks or impressions on ads, such as pay-to-click, pay-to-view, auto-surfing, automated ad clicking, and other guaranteed traffic programs.
An "Artificial Ad Traffic" disapproval has to do with the Inflating Ad Clicks or Impressions guideline.