Good evening,
I was in the mining world, near the portal in the protected zone, when I tried scooping up lava to fill my buckets. This lead to several interesting things happening. My buckets began to fill, though my original 7 buckets remained, but my inventory became full of buckets with lava in them. Also the lava disappeared from the pool! I figured that I would report this, and if you need the picture of the drained lava pool for your own records, let me know and I can supply them. If you need more info, PM me in game, and I can demonstrate further. Have a good evening.
TheNFunk

 

Upon leaving the mining world, the buckets seem to leave, but took actual inventory space when they were carried.