Hi,
The UPNP server on the 320 with firmware 2.0 and below has the problem and gives non-alphanumeric folders and files. The 2.02 firmware fixes that problem, but there is no downgrading, and a few folks have trouble with other features. Do your homework before you upgrade, but this will fix the UPNP server.
I have all of the WD TV Live versions but I don't have any problem connecting with either the network shares or the media server. Do you have the latest firmware on the WD TV? NAS and WD both using the same network name? That's all my guesses for now. Good luck
Correction regarding the WD TV LIVE, the newest version works fine, but the older Live and Live Plus, give me a "NO MEDIA FOUND", when trying to use the network shares. Will see if I can figure that out now.
Back again, try to enable the AJAXPLORER function in the applications for the 320, save settings, reboot 320 and WD TV LIVE and see if it is now available in your network shares on the WD TV.