Hey Mate, I am new at this, so I hope I am helping and not telling you how to suck eggs. Do you have these WADs in the root directory (not in a WAD folder)?? I have found that the need to be in the root directory for some things.
I just did this last night and loaded Priiloader onto my Wii. Look D7) in the link below. Be sure to read the whole thread. I started from the very beginning and
I had 4.2 on my Wii, so I had to go this way for my goal of getting a USB HDD with backups connected. In this process I put on Priiloader (took it off again as the kids could access it and put on Bootmi).