Well, that explains it!
Anyway, here's the screenshots took yesterday. Sorry about black blocks everywhere, but I like being anonymous :P
Photo Album - Imgur
Something noteworthy about the pictures.
Two first pictures are from toon1 giving away the Burden, two last pictures are the toon2 receiving the item.
Toon2 already had one Burden as you can see from his inventory, and there are no 2 Burdens in last picture? We wanted to capture the "Trade complete" -message, so the inventory did not update yet.