DLNA TV sees no music and only some photos

[chriswoodhouse]

I've got a QNAP TS-210 Turbo NAS.
I've created folders in the share qmultimedia and added all my music (effectively moving my iTunes library) and all my photos.
I have a Panasonic TV with inbuilt DLNA software, and having connected it to my home network over Ethernet, it could see the TwonkyMedia server on the NAS.
For a few days I could see both music and photos but after 6 days my NAS failed. I rebooted it and rebuilt it and it now works fine as a file server and a backup device. However, following that, when I open up the TwonkyMedia server on the TV, it only shows the photos and videos folders. It just doesn't see the music folders. Further, it doesn't see all the folders in the photos high level folder, and in some of the folders it does see, it says "unable to connect to server".
I have no idea if this is a problem with the NAS or with the TV, though my instinct is to blame the NAS.

Has anyone come across behaviour like this? Any ideas on next steps?

TIA,
Chris
Derbyshire, UK