USB external HD not recognised

Hi,

I have an old Iomega 500GB USB external HD ( http://www.amazon.co.uk/Iomega%C2%AE-500GB-USB-Hard-Drive/dp/B000JVRQUW)) that I thought I might connect to my WD TV Live. It has a power cable and a power switch (the latter seem to be a critically endangered species, thank heaven the WD has one as well…), and when I switch it on, you can hear the drive spinning up. However, when I plug the USB cable into the WD, you can hear it slow down and there’s no way it will be recognised. When I plug it into a computer, you can hear the usual disk activity of reading files.

Can anyone tell me if it _should_ work? The only limitation I found mentioned on the manual was that the WD can’t connect to iOS devices because they don’t provide a mass storage interface. That’s normal. But it doesn’t say much specifically about externally powered drives, as opposed to flash drives.

Could it be that I have the drive divided into two NTFS primary partitions? The WD seems to do fine with an NTFS pen, but it has a single partition.

Thank you for your time.