i beated the elite 4 of jhoto using few items ( 3-4 revives, few hyper potions ), and before starting my final fight , i used 5 revives and 5 hyper potion and also some super potions to heal them to max. and then, it showed connection lost when i had all my pokemons left and also defeated his first pokemon (i.e. Charizard). please, see into it. It has also happened few times before but never lost items as such....