Seems that if you die while your Personal Cargo is set, on a server with "PLAYER_DEATH_BLOCK_PUNISHMENT = true", you drop the cargo container's storage into space at your astronaut's position, rather than leaving it in its storage module.
However, the storage module will say that it still has all of its contents in it afterwards - this is incorrect, and placing blocks into the storage unit will correct the number of modules of that type displayed.