The CXN and other streaming products (NP30, Minx Xi, Stream Magic 6) will access the UPnP folders served by a UPnP server, rather than shared folders.
This is a universal standard. Some UPnP servers/NAS drives allow the ability to ‘tell’ the UPnP server to serve the content in the protected folders. Some don’t allow this.
There is no way for the CXN to access simple (or protected) network shared folders unless they are also served by a UPnP server.
Most of these NAS drives which have protected folders also have unprotected folders, which is the part that the UPnP server usually broadcasts.
For example, with most LaCie drives there are usually two folders on the ‘root’ of the NAS. The protected one is often called MyShare, and the non-protected one is called OpenShare. Anything that you don’t want served (personal documents, etc) can be kept in the protected drive and will not be shared on the network. Music/photos should be stored in the OpenShare folder to allow them to be ‘seen’ by network players or media browsers such as the CXN.