SD card not getting mount

I am trying to interface SD card with LPC1768 MCU using CMSIS file system middleware. I have configured the system in SPI mode using memory card drive(M0:).Initialization function returns the desired fsOK value.But the following function i.e. amount keeps on returning fsMediaError.What could be the issue ?

Here is the code:-

#include"lpc17xx.h"
#include"rl_fs.h"

fsStatus stat;

int main(void)
{
LPC_GPIO2->FIODIR=0XFFFFFFFF;
stat = finit ("M0:");
        \ 
if (stat==fsOK) {
stat = fmount ("M0:");
switch(stat){
        case fsOK:
                LPC_GPIO2->FIOPIN= 0xfffffff1;
        break;
        case fsUninitializedDrive:
                LPC_GPIO2->FIOPIN= 0xfffffff2;
        break;
        case fsInvalidParameter:
                LPC_GPIO2->FIOPIN= 0xfffffff3;
        break;
        case fsInvalidDrive:
                LPC_GPIO2->FIOPIN= 0xfffffff4;
        break;
        case fsDriverError:
                LPC_GPIO2->FIOPIN= 0xfffffff5;
        break;
        case fsMediaError:
                LPC_GPIO2->FIOPIN= 0xfffffff6;
        break;
        case fsNoMedia:
                LPC_GPIO2->FIOPIN= 0xfffffff7;
        break;
        case fsNoFileSystem:
                LPC_GPIO2->FIOPIN= 0xfffffff8;
        break;
}

}