Prospecting (Spell ID 31252) have a bug
if you have 1 Stack (20) Ore's like Iron Ore (ID 2772)
and you want to use Prospecting on the Stack it will prospect 5 from this, its ok, 5 ore's are prospected and you have an Stack with 15 Iron Ore
Here coms the Bug
if you want to prospect the next 5 one you can't do that, couse no item is inside the looting Bag
so
if you split this Stack from above in 3 Parts with 5 Ore's you can only mill 2 from this, couse the last one is corrupt
so
if you have an new Stack with 20 ore's and split it first in 4 parts with 5 Ore's , you can prospecting all