Hi Teak,
Thanks for sharing this information.
This seems exactly the same issue I had when trying to expand my DX4000 from 2 to 3 drives. It just did not work, clearly for a fault in the original WD install. In our case I managed to solve the problem with Intel RST driver even if this led to few cons. I find amazing to see how users left alone by WD managed to find different solutions to these issues.
I wonder whether it might be possible, by using RAIDCFG64, to have a more efficient RAID configuration with the o/s alone on drive 1, and data on the other 3 drives in RAID5 configuration.
Still it seems there is not an official WD solution to the lack of compatible hard drives.
