Bukkit

I consider this the general solution to the item-drop problem.  The only way to be really sure that REGENgine can't duplicate block items is by identifying those blocks it creates and then, by means of a system of event handlers, suppress the item creation when and if the block is broken.  For example, if R.E. creates sand, it may be made to fall arbitrarily far; only if it is tagged with custom metadata before and after the fall, or put in another global set, can we find it again.