Burned isos running in Gecko

I am in Europe, and my Wii is back home in the states. I want to play some games that I own on a friend's Wii here that he let me borrow, so I found the image files online, but when I burn them, I can't get the Wii to read them. I added Gecko and WiiLauncher to HomeBrew, but I still can't get them to play through that. Is there anything special that I need to do to be able to play these?

I found one original game here at the market, and that played fine through WiiLauncher, even though the game was NTSC and the Wii is PAL. So, I know that it is possible to do, it's just that these disks don't work. I have no mod chip, as I was under the impression that I can get what I need with HomeBrew. I also don't have any cIOSes installed. Just HomeBrew and the loaders. Ideas?

Read the rules.