Dragonhide armor and immunities

[Everchanging02]

I did a brief search for this in the forums and only spotted this mention. Apologies if I missed others or if it was intended as a definitive answer.

To the nitty-gritty.

Pathfinder Roleplaying Game Core Rulebook, Fourth Printing, page 154, Dragonhide:
"If the dragonhide comes from a dragon that had immunity to an energy type, the armor is also immune to that energy type, although this does not confer any protection to the wearer."

Pathfinder Roleplaying Game Ultimate Combat, First Printing, page 199. Dragonhide:
"If the dragonhide used to construct this armor comes from a dragon that had immunity to an energy type, the armor pieces also have immunity to that energy type, but only confer the immunity on the wearer if he is wearing a suit of armor made entirely of dragonhide from the same type of dragon."

Understanding that the latter is part of a new optional rule, I am curious if this 'improvement' was intended solely for that new optional rule.

[Pribam Pey]

I noticed this problem today, too, and it appears no one has addressed it yet, here or elsewhere. I suspect it is an error, given how cheap dragonhide is compared to the expense of even the lowest level of elemental resistance enchantment.