Now this is a mystery that begs for a solution

Take three items:

  1. One WD Elements Basic Storage (1TB) WDBUZG0010BBK USB 3.0 File System NTFS
  2. One WD Elements Desktop (1TB) WDBAAU0010HBK USB 2.0 File System NTFS
  3. One Samsung BD-P1580 - Blu-ray

Now to the mystery:

WD Elements Desktop (1TB) WDBAAU0010HBK USB 2.0 File System NTFS allows me to play films via the USB connection of Samsung BD-P1580 - Blu-ray

WD Elements Basic Storage (1TB) WDBUZG0010BBK USB 3.0 NEW File System NTFS is not being recognised by Samsung BD-P1580 - Blu-ray consequently I cannot use it to view films via the USB connector.

Please note: Both WD Elements use the NTFS File systems but only one is being recognised by Samsung Blu-Ray.

Can someone explain to me why that is?

Probably GPT partitioned versus MBR.

Thank you! You are absolutely right!