My understanding of how the system was supposed to work is that items left too long in the forge or furnace would turn to dust first, then nothingness and that items left in other containers (table, quench, stock caster) would become 'public property' after a while and anyone could take them.
It seems to me that server crashes interfere with the timer that controls this 'self-cleaning' feature. Maybe that countdown timer should be initialized for items in these containers as part of the server boot process (or is the timer at the client level?).