SD Card Error Upon first Run/Debug.

This function: 

Uint16 MMCSD_readNWords( Uint32* data, Uint32 numofBytes, Uint32 cardMemAddr )
{
    Uint16 i, j;
    Uint16 fifoDxrRdCnt;
    Uint32 fifoReadItrCount;
    Uint32 extraBytes;
    Uint8  fifoBuff[32] = {0};
    Uint8* fifoBuffPtr  = ( Uint8* )fifoBuff;
    Uint16 fifoThrlevel;

    /* Check the FIFO level to used. This is set in MMCSD_init */
    fifoThrlevel = ( MMCSD_MMCFIFOCTL >> 2 ) & 1;

    /* Check if the FIFO Threshold Level is default( 32bytes ),otherwise set it to 64Bytes*/
    if ( fifoThrlevel )
    {
        fifoReadItrCount = numofBytes >> 6;
        extraBytes       = numofBytes & 0x3F;
        fifoDxrRdCnt     = 16;
        fifoReadItrCount = numofBytes >> 5;

        if ( extraBytes )
            fifoReadItrCount++;
    }
    else
    {
        fifoReadItrCount = numofBytes >> 5;
        extraBytes       = numofBytes & 0x1F;
        fifoDxrRdCnt     = 8;
        fifoReadItrCount = numofBytes >> 5;

        if ( extraBytes )
            fifoReadItrCount++;
    }

    for ( i = 0 ; i < fifoReadItrCount ; i++ )
    {
	    while ( ( MMCSD_MMCST0 & 0x0400 ) == 0 ); //  DRRDY

        for ( j = 0 ; j < fifoDxrRdCnt ; j++ )
            *data++ = MMCSD_MMCDRR;

        if ( extraBytes )
        {
            if ( i == ( fifoReadItrCount - 1 ) )
                for ( j = 0 ; j < fifoDxrRdCnt ; j++ )
                    *fifoBuffPtr++ = MMCSD_MMCDRR;

            for ( j = 0 ; j < extraBytes ; j++ )
                *data++ = *fifoBuffPtr++;
        }
    }

    return 0;
}

hangs at  

	    while ( ( MMCSD_MMCST0 & 0x0400 ) == 0 ); //  DRRDY

The first time I build and run it, every time. When I reload the program, it runs correctly. 

Any clue why this would happen ?

Cheers,

Amanda