In versions0.485, 0.492, and 0.493 there is a bug with the refiner. When in the ship's inventory window, as the refiner is processing raw ore, it removes the raw ore (some base amount + wastage) and then adds a single unit of refined ore each cycle. When in the space view, this single unit of ore is added to the inventory, but the amount of raw ore that was consumed in the refining is NOT. This causes the ship's cargo volume to constantly increase when it should be decreasing. Since this number is used to determine when the hold is full, it will inappropriately cause the refiner to stop refining, mining lasers to stop mining, or tractor beams to stop collecting because it believes the cargo hold is full even though it isn't.

Switching to the ship inventory window and then back to the space view will correct the hold numbers to current values, but if you're still refining the error will resume.