Getting wrong data from SPI Flash SST25VF010A

I'm trying to interface an mcu (tm4c123) with external SPI flash memory SST25VF010A.
I execute the Read-ID instruction, but instead of gettting BF and 49 (manufacturer and device ids) – I get BC and 41.

Reading the status register also gives weird results – on startup I get 0x8 and after executing the write enable instruction, I get 0xC.
Looking at the datasheet and boot up values, I would expect it to be more like the opposite – 0xC on startup and perhaps 0x0 after write enable…

Here is my code:

void ConfigureSPIFlash()
{
    MAP_SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOD);
    MAP_SysCtlPeripheralEnable(SYSCTL_PERIPH_SSI1);

    // Enable pin PD2 for SSI1 SSI1RX
    MAP_GPIOPinConfigure(GPIO_PD2_SSI1RX);
    MAP_GPIOPinTypeSSI(GPIO_PORTD_BASE, GPIO_PIN_2);

    // Enable pin PD0 for SSI1 SSI1CLK
    MAP_GPIOPinConfigure(GPIO_PD0_SSI1CLK);
    MAP_GPIOPinTypeSSI(GPIO_PORTD_BASE, GPIO_PIN_0);

    // Enable pin PD1 for Chip Enable
    MAP_GPIOPinTypeGPIOOutput(GPIO_PORTD_BASE, GPIO_PIN_1);
    MAP_GPIOPinWrite(GPIO_PORTD_BASE, GPIO_PIN_1, GPIO_PIN_1);

    // Enable pin PD3 for SSI1 SSI1TX
    MAP_GPIOPinConfigure(GPIO_PD3_SSI1TX);
    MAP_GPIOPinTypeSSI(GPIO_PORTD_BASE, GPIO_PIN_3);

    MAP_SSIConfigSetExpClk(SSI1_BASE, MAP_SysCtlClockGet(), SSI_FRF_MOTO_MODE_0, SSI_MODE_MASTER, 125000, 8);

    MAP_SSIEnable(SSI1_BASE);

    uint32_t r;
    while(SSIDataGetNonBlocking(SSI1_BASE, &r)){}
}


unsigned char SPI_transmit(unsigned char data)
{
    SSIDataPut(SSI1_BASE, data);
    uint32_t r;
    SSIDataGet(SSI1_BASE, &r);

    return (unsigned char)r;
}

void main(void)
{
    ROM_FPUEnable();
    ROM_FPULazyStackingEnable();

    SysCtlClockSet(SYSCTL_SYSDIV_4| SYSCTL_USE_PLL | SYSCTL_XTAL_16MHZ |SYSCTL_OSC_MAIN);

    ConfigureUART();

    ConfigureSPIFlash();
    UARTprintf("spi flash ready\n");

    uint8_t res;

    // send Read-ID command
    GPIOPinWrite(GPIO_PORTD_BASE, GPIO_PIN_1, ~GPIO_PIN_1); // CE low
    SPI_transmit(0x90);
    SPI_transmit(0x00);
    SPI_transmit(0x00);
    SPI_transmit(0x01);

    // get response
    res = SPI_transmit(0xff);
    UARTprintf("received: 0x%x\n", res);

    GPIOPinWrite(GPIO_PORTD_BASE, GPIO_PIN_1, GPIO_PIN_1);  // CE high
}

Any idea what I'm doing wrong?
Thanks!