There is a bug (which can destroy things) with putting items in a container in your inventory, or picking stuff up after using a potion or spell to boost your strength.
The weight you are carrying is not updated properly when you place an item in a container in your inventory. This allows you to carry much, much more than you should be able to. After moving/dropping/picking up/equipping anything that changes your main inventory, the weight will be re-calculated, you may be carrying more than your maximum weight capacity, in which case nothing will go in your inventory. The same situation can happen after Bless, Heaven's Blessing or a strength potion wear off.
If you are over-loaded and equipping something causes this update, what it replaces will be destroyed. If you drag and drop something where there is a red X, it will be destroyed. I had a very full chest disappear dropping it where there was no red X once. This bug with containers is handy for moving a lot of stuff at once, but is rather dangerous.
