sdFat,Can't access SD card.Do not reformat No card, wrong chip select pin,or SPI

I am using sdFat library:

http://code.google.com/p/beta-lib/downloads/list.

and I am using AnalogIsrLogger sketch (found as an example in sdFat library ) , its attached.

the sketch has been compiled perfectly fine but when I open the serial monitor, I got a message that it didn’t recognize the memory card :

"FreeRam: 6753
Can’t access SD card. Do not reformat.
No card, wrong chip select pin, or SPI problem?
SD errorCode: 0X1,0X0
"

I have been using the SD card with adafruit data logger and arduino mega and it was working perfectly fine but it didn’t work using sdFat library !so does anybody know how to solve this problem?

using the normal SD library is too slow and I need to use sdFat library because it provides a fast sampling rate up to 100 khz (8 bit resolution )

AnalogIsrLogger.ino (15.9 KB)