Homebrew Confusion on loading games on USB

[bobguy243]

I have a 4.3u Wii and want to play a PAL copy of Beatles Rock Band off a USB. I have already made my system Region Free through Priiloader and put my .iso on the USB with Wii Backup Manager. Then when i launch WiiFlow or USBLoader, the game acts as if it will run but then begins to play the game in the disc drive. I have launched the .iso on Dolphin so I know the iso isn't corrupted.

Please Help!