Thanks again for your continued efforts on my behalf...
When you suggest "reinstalling" USB Loader DX, is that as simple as deleting it from my SD card and then redownloading? If that's what you mean then I've done it.
When I start USB Loader GX with no USB device it says "Waiting for HDD" and counts down from 20. I put in the device at 4 and it froze there, eventually the counter changed to -77 (???) and then USB Loader started and said "No USB Device Found." and took me back to HBC.
Try formatting your USB and putting the games back on it.
Sorry but if this doesn't work, I'm out of ideas :(