Why is Caliban wrong? Because, other than the passage about evasion, you can't find a rule spelled out in black and white stating that you can't make a reflex save if you're helpless? Please post your arguments why it's wrong (other than I always want my PCs to be able to make a save) and maybe you can convince us that we are wrong. I don't think we are, but if you believe that you are right, then you owe it to us to show us where we are wrong.
In my opinion, the only reason it's not spelled out in black and white, is because the designers just assumed that it was common sense that we wouldn't allow someone to dodge a fireball if he can't move and thus didn't bother to put it into writing.
Take a step back from the rules sometimes and try to look at the big picture of the overall game.
If you guys want to have luck be a factor in making Reflex saving throws (because that's the only way someone who is helpless could avoid being hurt by a fireball), then here's a house rule I would use. Make a Reflex save and only if it's a natural 20 do you save.
Since a natural 20 always succeeds - even if you needed a 32 on your reflex save when you aren't helpless (but you only have +4 on Reflex saves) a 20 would let you make it - we can assume it's the luck component of the saving throw. Obviously, in this case luck was the deciding factor, because your total of 24 didn't beat the required 32, thus the DM would have to describe some lucky break as being why you made the save.
I could see allowing this rule if someone is helpless, but if the character was allowed to make a normal reflex save with 0 dex, I still feel that the person could make the save (it's only a -5 penalty) far too often to make any sense whatsoever.
I personally, believe that the rules say you can't make a Reflex save when helpless and that's what I will continue playing with.
IceBear