Arthur, how did you unlock teleporter D? I copied my demo save over, and now I have collected all 17 of the visible tubes. Is there a hidden one? How do you get the 18th one to unlock the next section?
It's been a while since I played this game and I'm afraid I have no idea. One thing to bear in mind is that this walkthrough is from the original Desura release and I think the updated steam version changes some things, possibly the storage devices. All I know is that my Desura save won't work with the steam version so I cannot check.