See the thread in the DNS-325 Disk compatibility forums, I asked this same question there.
These Western Digital RED drives are going to be very popular, due to price and due to their firmware being tweaked for NAS and RAID.
I don't understand why D-Link wouldn't test their NAS boxes for compatibility with these new drives!
Now I am saving up for a DROBO, which is compatible with the WD REDs.
Good Luck.