Cool bug. Try to set a spared_koan var, 
and ignore the cube if you have that var.
Or drop the cube only by Lua code, instead 
of having it dropped on RoT file.
Or say that this is a feature for smart 
pkayers who know how to get maximum 
rewards, as long that getting both doesnt 
affect gameplay.
For Iris... Only show if you was friendly 
with the miner? Instead of not displaying 
if you was hostile.