Yeah, I remember reading it. Interesting how it worked fine in the 1st gen but totally unstable on the 2nd. I found a way to boot using the card on the 2nd gen mini. You need to press select and hold it until you see the backlight, after that it's all good.
But I switched to the 256gb SD card and will load the iPod only with .cue and FLAC images of the CD's. Less files will be stored, hopefully this will work.