hey Poog,
besides the fact, that I do not understand, what your bump map on the box is doing for you, (it is huge and the mapping type is cylindrical! it does not really show any effect, but it will for sure have an effect on the light it is reflecting. Either put it on properly or disable it! but this is not your problem!) I would change the lighting from "interior" to "product mode" and rather mess with the environment setting and the lighting a bit to bring that ground shadow back in again!
I guess this is the quickest solution for the moment being ! Your rendertimes will also be three times faster, if I compare on my machine, which, for an animation is crucial!
Personally, I would also change the material type for the box to plastic or advanced (personal pref, I like it better as it gives me more options to play with the material! ) and bring that white down just a tad (maybe 97%, nothing is that white !)
there are few other things here, i.e. your product "sticks" in the floor, which results in the slight white "brim" at the very bottom of the box.
With the lighting set to "Product Mode" this is not so obvious!
hope that helps!
cheers
designgestalt