LMS will advertise songs over UPnP, but plays only a small fraction of them

Hi, I'm running LMS 7.7.3 on x86-64 Linux and am running into a strange issue while using the UPnP functionality. I have a Grace Digital Mondo, and with said Mondo, I can browser through all the music from LMS. But when I go to play an album, the Mondo will display "Buffering..." for about 10 seconds before going to the next song, no sound plays, and repeat until the end of the playlist is reached. Almost all of my collection is encoded in Ogg Vorbis, but a few small files (< 1:30 in length) can be played on the Mondo, along with the few MP3s that I have.

The weird thing to me is that using a different UPnP server (e.g. MediaTomb) gives no problem with the Mondo; you can try the exact same album, and serving it from LMS won't work, whereas serving it from MediaTomb will work just fine. (I'd rather use LMS, because I already have other Squeezeboxes in the house, and LMS is simply a better server than anything else I've tried on Linux.) The Mondo has had problems with other UPnP servers that I've tried on Linux, FWIW, but I don't think the problem is with the Mondo in this instance, because it can play some songs from LMS.

I tried flipping the plugin.upnp logging setting to debug, but nothing unusual (to my eyes, anyway) showed up in the logs (sample output below). I also tried flipping some of the networking logging, but nothing interesting (AFAICS) came out of there, either.

Any ideas on what could be wrong, or ideas for debugging I could do? I looked at the logs for versions 7.8 and 7.9, but none of the improvements sounded like they'd make UPnP any better.

Thanks in advance,

Output from flipping the plugin.upnp logging:

[14-10-05 21:07:30.4500] Slim::Plugin::UPnP::SOAPServer::processControl (136) Invoking Slim::Plugin::UPnP::MediaServer::ContentDirectory->Browse( {
BrowseFlag => "BrowseDirectChildren",
Filter => "dc:title,upnp:class,upnp:album,upnp:originalTrack Number,id,res,res\@protection,res\@duration,upnp:s earchClass,upnp:artist,upnp:genre,upnp:albumArtURI ",
ObjectID => "/g/4/a/464/l/317/t",
RequestedCount => 1,
SortCriteria => "",
StartingIndex => 4,
} )
[14-10-05 21:07:30.4503] Slim::Plugin::UPnP::MediaServer::ContentDirectory: :Browse (695) Executing command: titles 4 1 album_id:317 sort:tracknum tags:AGldyorfTIctnDUFH
[14-10-05 21:07:39.8529] Slim::Plugin::UPnP::SOAPServer::processControl (136) Invoking Slim::Plugin::UPnP::MediaServer::ContentDirectory->Browse( {
BrowseFlag => "BrowseDirectChildren",
Filter => "dc:title,upnp:class,upnp:album,upnp:originalTrack Number,id,res,res\@protection,res\@duration,upnp:s earchClass,upnp:artist,upnp:genre,upnp:albumArtURI ",
ObjectID => "/g/4/a/464/l/317/t",
RequestedCount => 1,
SortCriteria => "",
StartingIndex => 5,
} )
[14-10-05 21:07:39.8533] Slim::Plugin::UPnP::MediaServer::ContentDirectory: :Browse (695) Executing command: titles 5 1 album_id:317 sort:tracknum tags:AGldyorfTIctnDUFH
[14-10-05 21:07:47.0180] Slim::Plugin::UPnP::SOAPServer::processControl (136) Invoking Slim::Plugin::UPnP::MediaServer::ContentDirectory->Browse( {
BrowseFlag => "BrowseDirectChildren",
Filter => "dc:title,upnp:class,upnp:album,upnp:originalTrack Number,id,res,res\@protection,res\@duration,upnp:s earchClass,upnp:artist,upnp:genre,upnp:albumArtURI ",
ObjectID => "/g/4/a/464/l/317/t",
RequestedCount => 1,
SortCriteria => "",
StartingIndex => 6,
} )
[14-10-05 21:07:47.0183] Slim::Plugin::UPnP::MediaServer::ContentDirectory: :Browse (695) Executing command: titles 6 1 album_id:317 sort:tracknum tags:AGldyorfTIctnDUFH
[14-10-05 21:07:54.0078] Slim::Plugin::UPnP::MediaServer::description (99) MediaServer.xml requested by iTunes/4.7.1 (Linux; N; Debian; x86_64-linux; EN; utf8) SqueezeCenter, Squeezebox Server, Logitech Media Server/7.7.3/1375965195
[14-10-05 21:07:55.7310] Slim::Plugin::UPnP::SOAPServer::processControl (136) Invoking Slim::Plugin::UPnP::MediaServer::ContentDirectory->Browse( {
BrowseFlag => "BrowseDirectChildren",
Filter => "dc:title,upnp:class,upnp:album,upnp:originalTrack Number,id,res,res\@protection,res\@duration,upnp:s earchClass,upnp:artist,upnp:genre,upnp:albumArtURI ",
ObjectID => "/g/4/a/464/l/317/t",
RequestedCount => 1,
SortCriteria => "",
StartingIndex => 7,
} )