Nice, its a good library and makes reading and writing to the SD card easy. There are a few parts in the sd_raw.cpp and config files that need to be changed to get reliable operation on the arduino. Something that isnt obvious is that in the library he specifies pins 5 and 6 of analog in(2 wire interface) as sensor pins for card insertion and read/write tab. You can disable that in the code but the easiest way to check if your code is working is to ground pin 5 and 6 of analog in. I found this out by accident when I was holding the arduino and tilting it and trying to figure out why it wasn't working. Every now and then it would find the card, my hand must have provided a ground. ;D
I've gone through the code and commented out various bits and changed a few things so that it works well but have to go through and make sure that all the changes work ok and document what I've changed.
Anyway yeah ground analog pin 5 and 6 and it should work.
If you want to remove the code then look in the config.h files and comment out where he defines PortC 5 and PortC 4 pins. Then remove the code that checks for memory card insertion (there's 2 functions and some code in the sd_init function) and it should work fine. If you want to leave it then you'll have to connect your memory card socket to the 2 pins for insertion and read/write checking or ground the pins.
Also if your after an SD card socket this looks nice (i found this after I'd de-soldered a memory card reader to get the SD socket lol)