Thanks for the answer. The different settings didn't help, now I'll try to patch the game (whatever it means, I'll have to learn it first).
Also tried to reinstall cios16 from the wad file (the original that I used to softmod the wii), but no luck.
Now this is strange. I tried to extraxt an ISO from the wbfs to patch it, but every program I tried said that this ISO was corrupt. So I deleted it and the wbfs as well, and copied it back from the original source (I read somewhere that reinstalling has solved another guy's problem), and it works now. I have no idea how it went wrong at all, but it's all right. Thanks for your help.