The powder measure has an arm that connects from the powder measure to the base for a manual return. It'll also return w/out this, but it's not as solid.
When the shell goes up, it all activates. When the shell comes down, there's a powder dump. I think that maybe the measure is not closing fast enough or something. I'll go watch it (no powder in place) and see if I can figure it out.
Powder is Xterminator- shouldn't be any issues there.
EDIT:
Googling on it, I'm probably just cycling too fast. I'll clean and tighten everything, but man, it's a mess when that powder spills. I dunno... the Dillon's find for pumping out 500 rounds of prairie dog ammo, but if I'm just doing 50 rds or so, I kind of like the old fashioned way of a single stage press and RCBS powder measure.