Something is causing us to not take damage at all. I believe we figured out the cause.
Everything worked fine for a little while, we took damage at the beginning, and died a few times to hunger while logged out. once we placed out protective barriers, it stopped us from taking damage inside it, like its supposed to, but we still took damage outside the barrier. Now, all of a sudden, none of us three take any damage whatsoever... fall, drowning, puma attacks, etc... If i type /killme, it fixes the problem, until I stay in my protective barrier long enough to where I would die without it. Once the barrier "saves my life", then I no longer take damage again.
Its happeneing the exact same way with all three of us. we tried in 0.6 and 0.6.3 with the same results.