Did you become encumbered when you swapped rings? There is a bug with placing items in containers in your inventory, or with spells/potions that boost strength, which can destroy items. See;
major problem with weightA couple people have run into disappearing chests. Some have found that they were visible at night, or when they stood at a certain location. One person had a chest disappear when they put it down outside a building, but it was visible when they went inside, and they could get their stuff back using Telekinesis.
