I would drill all the way down to the Ad Group level, in the keywords tab and click the customize columns link under the date range and to the right. I'd show t

I would drill all the way down to the Ad Group level, in the keywords tab and click the customize columns link under the date range and to the right. I'd show the quality score as a column; check all the quality scores and minimum bids. Then I'd check all the status starting from the keyword level up to the campaign. Lastly if nothing showed up there I'd go back to the keywords and put my mouse over each and every keyword magnifying glass to find out if ads are being served. Then if it didnt work I'd call google and ask them for help. Hope this helps!