Anti-Pro

So I have been building my first master piece space station and have ran into a problem. I started out with a Oxygen Bubble Distributor to cover the starting platform and placed some strongboxes down just fine. I then built a walkway out from a side and constructed a room to make my living quarters. I have the room sealed with a doubled air lock door and have a oxygen sealer inside to provide oxygen. I have a good seal and have been able to start my withcery station just fine, until I tried to place down a strongbox, and it broke, throwing out all of my items. I thought maybe it was just a freak accident, so I placed another one down to the same outcome. Then I tried to place a redstone furnace and got the same result. The only thing I can tell to be different is that my room has a oxygen sealer and 2 airlock system, rather than the oxygen bubble. Please help.