Latest BIOS for this mobo, yes, thanks, gg.
With interest spiked by the Wikipedia statement and with nothing to lose I have
- Partitioned the cloned HDD in to two using the same copy of Acronis Disk Director that I had originally used to partition the donor HDD before I changed my mind and started again from scratch. The only difference this time is that the second drive letter was Q rather than D because all the letters in between are now used for other physical and logical drives
- Converted both partitions on the clone HDD to unallocated space - again, replicating what had been done in the past to the donor HDD
- Switched off the media server
- Repeated the cloning operation using the steps listed in my original post apart from those related to changing Access Mode; this time it was left as Auto
Guess what?
Now that the clone has lost all trace of its origins in a Seagate factory it now boots as Access Mode = Auto, just like its parent, and not Large any more.
Seems Wikipedia was right and this is a BIOS compatibility thing.