Can't see files in shared folder with DNS-320/325

Hi,
I well installed Serviio 1.3.1 on my DNS-320 with fun_plug 0.7
following these posts : "HOWTO: Serviio 1.1 on Zyxel NSA 325" and "Serviio 1.2 on DLINK DNS-320"

FFmpeg and Java are running correctly
I can see Serviio running with Serviio Console 1.3.1, I can set the library and presentation
I see the shared folders in my device but impossible to see any file
Permissions of shared folder is set to 777

The log file give me this info :
2013-11-22 23:49:06,797 WARN [LibraryAdditionsCheckerThread] Folder '/Volume_1/Films' is either not an existing directory or cannot be read due to access rights

Is there some line to modify in serviiod.sh or serviio.sh ? I tried with Serviio 1.2 it's the same result.
Can anyone help me to find a solution ?
Regards,