Yes, is very strange. The interface is displaying in the game, I assigned to current character and defined the interface area. I have set the image as active image. You can see in my screenshot that the image (P, at the top) shown. The button is working, also I have put a sound in the action tab and it works...
I have a lot of interfaces with buttons that are working fine, I tried to create the virtual keyboard interface with copy&paste from a old interface and then I modified the interface adding the bg image and moving the hotspots but it still no works.