The code looks good, I'll run it against my hardware and let you know what happens. This is a long shot but could you email me a digi picture of your card with its soldered connections? I've PM'd you my email address.
Post up the code your using in your arduino sketch., that could help. If the card does nothing, then try making a simple sketch which just initializes the card and then prints out the sd card info. That should tell you if the card was initialized and is working or not.
Yeah I finally got it to all compile properly. I put the .c and .h files into a directory, renamed the .c to .cpp and it compiled automatically. I had to change a bit of the code as he uses the C99 standard and I don't know where to add flags when the arduino environment automatically compiles. I probably will just use the low level read/write routines although the fat16 would be interesting. Just wanted to use robust sd/mmc access routines.