XxPoNaGeXx
I assume that you are experimenting with ads on your website and the image from ad.afy11.net is one of the ads.
As far as I know, your problem can only be solved by switching your website back to http (which would be a really bad idea) or by persuading your advertiser to switch to https. Unfortunately you can't force them to use https which often only leaves the option to look for other ad companies. It should be worth to ask them, even though I doubt they will care if they still deliver over http.
Often it's not the ad company you have a contract with that delivers over http, often it's a sub-contractor or sub-sub-contractors who do that and you have not the least control over them.
As far as I know, Google adsense should deliver all their ads over https.
