Disc loaders are severly outdated, use a USB loader like Nate said. The only thing that'll happen is loss of colors because you're playing a NTSC disc on a PAL system. Try using a region free loader or change your Wii's system locale using Priiloader or something similar.
If you persist on using discs use DVD-R Verbatim if possible. These give the best results. Also, check you have the option error 002 fix on. It should be in the options menu IIRC. In any case, don't use DVD RW's. For some reason these don't work.
This post has been edited by blastermak, Sat, August 27th, 2011 at 13:13