I recently had a new idea why a few might be getting so sick on this ride. First I went to the warning postings and saw that it doesn't mention that which I was concerned about.
The warning that this sign does not contain that is prevalent on Mission Space is to keep your head and eyes facing forward at all times. The reason of course is because turning ones head to the side will betray the direction that you thought you were going and in turn, really mess up your head. I believe that this may well be true on the bowl screens despite how slowly they might be moving sideways. Any amount would tend to screw with the brain.
Just a thought.