[H] Stumper on GPT Protected Partitions

[tmservo]

Ok.  Had a 3TB drive get setup in a PCH (Network Media Tank).  Pulled 
it.  Went to a Windows station, ran DiskPart, cleaned it off.   Put it 
back and initialized it GPT.   Copied files onto it.

Machine A (the one that did it) sees all the files and data -perfectly-
Remove the drive from USB and connect to anything else, and everything 
else sees NOTHING, only the GPT Protected partition that Machine #1 
thinks is gone.

Any hints?