No, I wasn't clear - the SD is powered directly from the 3.3V supply pin on the Arduino. I'm using the voltage divider for logic level shifting the 5V output pins from the ATMEGA to the SD card. The data line from the SD to the ATMEGA goes directly.
It's good to hear that I should expect to need to make changes to Roland's library to get it to work in Arduino, since I was starting to think I was really lost.
Thanks for the feedback.