Problem when defining as Media Placeholder

Hi,

I 'm using Keynote 6.5.3 (latest version) on a mid-2011 iMac on Yosemite 10.10.3

I am creating a new Master slide, where I have various elements on top of a photo that I want to "Define as a Media Placeholder" so, the user should be able to change the background photo.

As long as I am editing the Master slide everything looks correct.

When I go on and create a new slide based on this Master slide, the photo somehow gets arranged on top of everything and hides them!

Apparently this is a bug but has anyone managed to figure a way around this?