So here I was...scrolling through the games in USB Loader GX...when BAM! my screen is black background with white letters.
"Exception (DSI) occurred!"
Oh no, just when I was about to wrap it up. I had just downloaded cover art the day before and now...this!
Long story short...my Wii crashed because one of the cover art files did not download cleanly through USB Loader GX. When USB Loader GX tried to read it, it choked. I had another system with a clean file, overwrote the bad one and...voila! Problem solved.