Problems connecting two drives to wdtv live

I have a 1 year old wdtv live running the latest firmware it has been 

owrking well with a 2tb external usb2 drive connected to the rear port,

I have just connected a second 2tb external usb2 drive to the front port 

but now the contents of the original drive have dissapeared! Is there a

particular method that has to be used when having two drives connected?

Should I use a usb hub or have one drive connected to each port?

Also I have the media library turned on is that correct? 


Which firmware version do you have? Keep in mind that WDTV Live used to support only 2 TB drives. But if you update to the latest firmware the problem should be solve. Also test the drives with the USB hub.