Basicly you can always say if a game doesn't work:
1) Try CFG-Loader. It has the best compability (GX is one of the crappiest loaders).
2) cIOS rev14 is the best cIOS (besides for ripping games and playing Dual-Layer games)
3) If the game region is different from the disc region, play around with forcing/patching the Video Mode.
4) Set the language to default.
If that all doesn't work, it's a bad .iso, or something went wrong during the transmission.