Network shares are not mounted on the PBO until they are required so this poses a problem sometimes if you try to access them via an rss feed. The best thing to do is to mount your shares on start up as indicated here:
http://tinyurl.com/3ox4q6j and then to use that mount point in the movie jukebox. Note that if you mount it at the same place as where your other movies currently resides then you will be able to use the same jukebox as your main one. For example assuming that your movies reside on an external USB on the directory
/tmp/usbmounts/sdb1/Movies/
You could create a directory /tmp/usbmounts/sdb1/Movies/network/
Now you could mount your network public directory onto that directory "/tmp/usbmounts/sdb1/Movies/network/" using the procedure explained at the link.
Note that you should make sure that the USB Drive itself is mounted before you attempt to mount you network public directory. This can be accomplish using a small script or just adding a "sleep 60" command in the /usr/local/etc/rcS before issuing the mount command for the network. That would gave you 1 minute for everything to settle before you mount the public directory. A script is more efficient and I can help with that once you decide exactly what you want to do.
The beauty of all this is that when you issue the command: "./jukebox_update.sh -p /tmp/usbmounts/sdb1/Movies" all the movies/videos on your NAS will get included all in the same jukebox.
Anyhow let me know how far you can go with that by yourself and ask for help when needed. Note that the example given in the link uses a different mount point than what I am suggesting so you will have to adapt the mount command accordingly.
Cheers !!!