Apparently Airpush Detector doesn't alway catch everything, nor does Addon Detector. In my case, it didn't show anything. So I compared recent updates with apps that keep turning themselves on and running in the background (as shown on ATK). I deleted the updates on both of my apps that were suspect and went back to the prior versions. (I keep backups of all my apps, so I can restore earlier versions as necessary) and the ads stopped. Astro File Manager and ES File Explorer, among others, can back up your apps into installable apk files, which can be restored at any time.