I am not 100% sure of the details, and even if i was i wouldn't post on how this glitch is performed, but i made a ton of iron pickaxes from iron i had in my backpack, and then it somehow got nulled and i got all my iron blocks back, aswell as the picks i had made.
i also made 10 stacks of gold ingots, placed them from my backpack to my inventory, and then the iron ores from my backpack came back.
I am expected to do the right thing, and dump my gold, but im not 100% sure how it happened, so i won't dump the duped items..for now.
EDIT: fml, i got nulled again and this time my backpack went back to its original stuff, i lost 25 stacks of gold ore.. wow... just wow...
If there's anything you can do cav that'd be great, if not fix this damn glitch for me!
EDIT: also, i think i've found the "how" of the glitch, every time you teleport, the backpack get's reset to when spoutcraft first got re-enabled.