this is a basically a double post from the PS3 thread, but since I just verified that it's working on both my PS3 and 360...
It's working on mine, but where I thought I had a problem, was just something that took time.
My Setup:
DNS-321 fw1.01
DHCP based IP in 192.168.1.x range
RAID 1 with 640GB
I unchecked "root" and set it to use \Media
I put my files in Video, Pictures, Music directories respectively (with lots of sub-folders)
PS3 fw2.60, static IP
Initially, when I did it, only music files came up (the first thing I set up), now several hours later, all my movies and photos show up as well.
One annoying quirk, on the PS3, when I tell it to browse by folder, it starts with the Media folder, rather than Music, Pictures, Video. I expect that since the share point is Media, that the PS3 should start with the contents of Media, not by making me select the Media folder
Anyway, the core point is, if your PS3/360 connects to your DNS321, but shows no files, it may be that the DNS321 is still processing the files. Just like Windows Media Server does. It takes time.