I think the problem is not with the simulation, but with the visualization tool… 
Looking at the positions of the hits, it seems that the simulation is working correctly (good news). But the restGeant4_ViewEvent visualization tool I think is not. It is showing the event and the geometry in different scales, or something like that, and so, it looks like the event is out of the volume when, in reality, it is not.
Well, I lost a lot of time on this, but at least nothing important is broken 