Probably what's happening is you have a base set that has one item, and then you layer the other item over top of that. As a resul spellcast is tryring to equip both items, but the game will unequip your ammo if you equip a ranged item and vice versa.
Whenever you equip aureole you should empty out your ammo slot <ammo>remove</ammo> and when you equip ammo you should empty out your range slot <range>remove</range>
took me a while to figure out what was going on too.
XI Wiki



