Audio presentation failed after visibility changes

Newbie: Happily using 0.6.2 on WinXP with Samsung UE5000 C/D series - very impressed with the solution and hard work donated - thanks. Installed about 9 days ago.
All well, reasonably large music collection (106GB) in 4 folders, presented nicely on TV.
Decided to change presentation of audio, turned off several categories. Around same time started removing duplicate music - some entire folders, some just tracks.
Then noticed Music category display on TV wrecked - mostly empty screen with only 1 category at a time - seem to be stuck in genre. Video indexing all displayed fine.
Have tried reverting to status quo, no change, have simplified down to 1 music folder, have stopped and started Serviio service, forced re-index, all no better.
What to try next, please? Seems have found config funny or (deep breath) a bug perhaps?
Occurs to me that the tool for finding duplicate music was .Net - based - so the ghastly MS .Net framework was installed and updated. This is probably the change that caused the difference.
Wonder if this clobbered some .DLL somewhere or is interfering with this Java-based app.
Might try removing and re-installing Serviio unless anyone can come up with a better suggestion?

[zip]

try eto enable detail logging to see what's going on. It might take some time to bring the library up to the required state if you move a lot of files on the drive.

Trying to identify if this is a server or client issue: had hoped to use VLC 2.01 but too buggy to be useful. Installed 2.02, pointed it at Serviio, found DLNA server, nothing shared. Turned off 'parse output' in VLC - and behold all the music is there and plays fine.
So it looks as though my Samsung TV DLNA client can't handle something about what Serviio is sharing in the audio side - probably just the sheer scale of files being offered - TV just reports that nothing is shared - clearly not the case.
So issue sorted of resolved i.e not primarily a Serviio issue.
But not a working system.
Video continues to be great.

Interesting experiment: pointed a new installation of VideoLan at the Serviio server - which immediately started hammering the disks containing all the shared video and audio files. VideoLan sat there for 30min while Serviio apparently spent all that time building a new set/index/list of shared media.
Don't understand this at all: if Serviio already has a set of indices for shared media (updated automatically), then why did appearance of new DLNA client seem to trigger a complete trawl of folders of shared material.
*IF* this is what is happening when Samsung TV is told to look at shared audio, no wonder Samsung DLNA client times out, reporting 'No media shared' under the Audio category.

Why does Serviio do this? Surely simpler for the code to use existing data structures to provide info to a new client?

[will]

The problem with VLC is that it recursively goes through EVERY folder requesting it's contents. Normal clients request one at a time.