W00t! I upgraded to OS 5.5 running Snow Leopard, H8000 connected via ADAT and it's working flawlessly.
SanDisk 32MB Stock card did not work.
I'm using a 'SanDisk Ultra' 2GB Flash card with the stock PCMCIA adaptor.
Kingston 4GB card did NOT work.
The retailer tech mentioned, there were no problems with the hardware, it's just the unit is sensitive to the type of cards. He mentioned there might be a 2GB limit problem. I'm guessing he tried another 4GB card aswell, which did not work. He did try a couple of other cards. Some worked, some didn't.
Hope this helps.