Update: 26th Sep 14
WOS replaced the box with another unit. I have it on for around half an hour (with a minimal setup/configure) and deep standby on this box appears to be working. I can switch the box into deep standby and switch it back on 30 seconds after the blue LED comes on with it booting without problems - and with the hard disk and network working.
I would suggest a box that requires it to be in deep standby for 10+ minutes before it will correctly start up again is faulty.