Learning Houdini and having trouble creating “raining boxes”.

I'm emitting particles, copying a box to each particle, then killing the particles after they're born. I then specify $FF for the RBD Packed Object's creation frame, but boxes are only born on the first frame, not every frame. This worked fine on my laptop but isn't working on my desktop at work. I've attached the simple scene file in hopes someone can point me in the right direction.

Is this the best way to achieve the effect? Should I be going about this another way? Thanks in advance for any help / guidance.