I Report the problem to Ning support as:
"Why http://socialning.com/chat does not show Google Banners? Nor TOP, nor Right, nor Bottom?
CHAT is a very important place to displace banners, and one get some cents to pay the rent.
Tell your Technical Team to review my http://socialning.com/chat and see why does not display Google Adsense Banners?"
And this is the ANSWER I got?
"It's possible that Google doesn't allow for ads to be run on specific pages of the network, or that Chat is interfering with your ad code. Unfortunately we can't always make accomodations for third party scripts, so your best bet would be to refer to Google's Adsense support or creators.ning.com to see if they can help with that custom code. Since Chat is running in the footer you might also consider removing the Chat tab.
Adsense is being executed on this page, but Google is choosing not to show ads. It's not an issue with Ning per se.
Yeah, I think Blake and Phil are both right and probably provided the correct answer to your request. You might want to remove some of your third-party code and see if it still works the same way. Could be a conflict. Could be a question for Google. Hard to say for sure.