Yesterday I re-charged an arcane robe. When I came to charge the new items I'd made I couldn't find the stack of gems. The only conclusion I could reach was the re-charge had used the whole stack. (56 gems lost! ) I just, again, recharged an arcane robe (not the same one). To test the theory I put just 2 stacked gems in my pack. Sure enough, both disappeared. This only happens when recharging existing arcane items, not when making new ones. Bug report submitted.