When someone dies and you go to loot their corpse (not their bag - the body), and you move to place something on their body you lose the object. You receive a message telling you that you can't place items on a corpse, but the item is not returned to you.

Are you sure?

Try closing your inventory and opening it again -- sometimes it doesn't show up immediately.

Positive. Try placing a bag onto a corpse, that is what I did. I ended up losing my potions and wands.

I tried closing the inventory, I tried looting the corpse, moving the corpse (thinking it may have fallen on the ground under it). I tried leaving the area and coming back. Nothing worked, the hotkeys also did not function. Logging off and back on only resulted in the hotkeys being removed. The corpse ate my bag! :(

I thought I had this happen with a set of armor, however I ended up finding it on another page of my inventory. I do know if there is a bug with bags/box/containers, but normal stuff is not deleted.

Don't even ask me why I tried to put my bag on a corpse. I just noticed I was encumbered and after I had gotten the body to safety I realized I'd be unencumbered if I dropped the bag. So I tried to put it on the body... hey! I was tired and wasn't thinking clearly.

It likely only affects containers.

so- you put a container in a container! Sacriledge!

You're trying to unwrap the means which create the universe, like that Box Dude.

Mort so- you put a container in a container! Sacriledge!