Hi, first post on the forum to tell you that I have the exact same problem.
My setup : Black Wii softmodded successfully using Modmii 6.1.5, build,a,UNEEk+DI using Modmii, everything works perfectly (HBC, Usb loader GX, etc). I use an external 500 GB HDD. Both HDD and SD formated to Fat32 with...