I had trouble getting a patched NSMB to work on a PAL Wii (system menu 4.2E) with WiiKey v1, it kept saying there was an error and I had to restart the Wii just after putting the disc in.
I followed steps 1-4 from http://www.wiihacks.com/recommended-faqs-g...os-4-2-wii.html
Now it works...