Well that just doesn't bode well at all! Her scream though after that announcement is just absolutely hilarious! One can only think of what that loss of gravity is doing to her in the shower and all the problems that will now occur due to not being able to use the ground normally(none the less what problems it is now causing throughout the ship)!
Lovely attention to detail to make the plants leaves slowly experience zero gravity as well! Though its quite mysterious how the loss of gravity would cause the shower to unlock. Just seems like another problem that is caused by zero gravity!

for the door to unlock i would say its a security measure, when an emergency occur doors unlock to make sure that every one can escape.

And the ship might be an old one and Mezza might have shorten hers maintenance list XD