Aside from that - Have you logged in and double checked your daily budget, and other settings?
LisaB
If you still don't see your ad, try logging into your account and double check the campaign settings: like target language, target country, your daily budget, and distribution preferences...
If there's a problem with an ad or campaign you should see a note in red... For instance if a campaign is paused it will have paused in red next to the link...
LisaB