This may be working as intended, but an item that allows the character 3 charges of "summon earth elemental" does not work because it considers it just like a Summon Creature spell. Since my character is not a caster of any sort, he has 0 summoning points and "lost control", instantly removing any summoned earth elementals and making the item entirely ineffective for this purpose.
Yeah, I think that item is just for mages, but it did the same for me a few months ago.