So it seems like when Traders accepted their magic deal and started learning Lunar Magic, Huldah's Pall wasn't updated to accept them as acceptable targets...

You gesture, muttering a quiet riddle to invoke Huldah's trickery.
A pair of immense ghostly hands sweep forward to grasp Trader in a translucent embrace!
As the hands tighten, they pass completely through him and fold back on themselves to snap around you!
You are bound by your own Huldah's Pall spell.
Roundtime: 2 sec.

Please fix.

Thanks.

They would have seen this message if so?
>>You gesture at Trader. Traders's mask of faint reddish smoke glows obtrusively. Your spell pattern is thrown out of control and loses its target!

It's very possible that the spell was hardcoded with specific guilds and Traders weren't updated to be part of that list. Grejuva just fixed BOTF for not recognizing Traders as magic-users just this morning.

Other possible abilities that may not be working properly against Traders?

Mage's Lash
Mana Torment
Aether Wolves

Thanks, Grejuva!