If the GC Loader you are using successfully loads some games with no problems, then I would probably say that some games are just not compatible I know I've found maybe 2 PAL Wii games that I can't load even while forcing NTSC, but it works with the majority of my other PAL games. I'm guessing that not every game will ever be 100% compatible, but hey it's free and for the most part works great 
