1) Download Hermes cIOS 222/223 v4. Use IOS 249 to install, and choose to install 222, as 37 merged with 38. Do this again for 223.
2) Set USB Loader GX to load games with IOS 222 or IOS 223 if you also installed that.
3) Set the video mode for monster hunter to Force NTSC
I had the same...