Do you get the "Welcome to mopub! click here to test as, you can now set up a new campaign to serve other ads" ?, because that's wat I'm getting.
I found out that in Mopub>inventory when you put MoPub Demo Order on pause, it dissapears. But it doesn't show real ads after that aswell.
I also found in some screenshots of others, that in Global Segments their Banner Ad and Admob have a ECPM that greater than 0.
Mine is 0 and I don't really know how to change that. So I guess we both have the same issues.