Adding NPC's to instanced zone

[Randymarsh9]

I want to add a monster to Arena version 1, so I tried zoning into arena and then spawning it, doing #npcspawn add, and then changing the version of the monster in the DB to one, but even after a server restart the mob showed up in the regular arena and not the instanced one. So then I tried actually going to the instanced one and then spawning it, but it did the same thing. Is there another thing you must edit to make monsters in an instance without putting them in the main zone?