I found my old AR MAX flash drive, which is guaranteed to work with the PS2. I tried installing FMCB again but for some reason I'm having the same problem I had two months ago - FREE_MCBOOT.ELF is not in the list of items on the drive. To put it another way, it's like AR MAX goes into the INSTALL folder first (from the noobie package) rather than finding FREE_MCBOOT. Both are properly installed onto the root of the drive and the drive is formatted for FAT*.

*For whatever reason, if I try to format it in FAT32, it tells me that the drive is too small and cannot be formatted.