It's been driving me crazy too. Nothing would work but I found a solution!!!...
I have a PAL Wii, I bought a PAL Black Ops Disc from EBAY and used USB Loader GX to rip the disc ISO to my harddrive.
In the "Game Load Settings":
Game IOS: 250
Block IOS reload: ON
All other settings: Global
In the "Loader Settings":
Video mode: Disc Default
Dol Video Patch: OFF
Sneek Video Patch: OFF
VIDTV Patch: OFF
Aspect Ratio: System Default
Game Lang: English
Patch Country Strings: ON
Ocarina: OFF
Private Server: OFF
Loader IOS: 249
Games IOS: 249
Block IOS: ON
Hooktype: VBI
Wiird Debugger: OFF
Debugger Paused Start: OFF
Channel Launcher: Main DOL
