Sainsmart 3.2" Touch-screen : How to put to sleep?

Okay, this is day#3 for me, new to Aduino, and first post here. I'm using a Mega2560 card, with a Sainsmart TFT_320QVT display, with an ElecFreaks TFT LCD Mega Shield 2.0, and the UTFT drivers.

The UFTF drivers offers a lcdOn() and lcdOff() function, but only for PCF8833 based controllers.

I've modified the driver to support the SSD1289 (bits between the MD: Start/End):

void UTFT::lcdOff()
{
	cbi(P_CS, B_CS);
	switch (display_model)
	{
    	case PCF8833:
	    	LCD_Write_COM(0x28);
		    break;
    // MD: Start
        case SSD1289:
            LCD_Write_COM_DATA(0x10,0x0001);
            break;
    // MD: End
	}
	sbi(P_CS, B_CS);
}

void UTFT::lcdOn()
{
	cbi(P_CS, B_CS);
	switch (display_model)
	{
	    case PCF8833:
		    LCD_Write_COM(0x29);
	      	break;
    // MD: Start
        case SSD1289:
            LCD_Write_COM_DATA(0x10,0x0000);
    // MD: End
	}
	sbi(P_CS, B_CS);
}

This works, in that it appears to shut down the graphic controller, but that leaves the backlight active to glow "through" the now blank display to give the same effect of the white-screen when the module is first powered on.

Is there any known way to control the backlight? Any discrete pin on the shield/display module that can be tweaked to gate the backlight?

Regards,

Mike