Wii .iso's not working with Dolphin

I tried using the nkit.iso downloads for Metroid Prime 3 and Mario Strikers Charged, however Dolphin doesn't recognize the unzipped disk images as Wii games. Instead, the GameCube icon appears next to the game, and when launched, Dolphin freezes completely and becomes unresponsive. wbfm files work fine, so I was able to get the games through that method. Not sure if this problem has been noted, so just thought I'd say something.