Hi Lespaul, and thank for the reply!
What happens to me is that there is a small gap exactly at the -10s mark at the end of a track. The gap can be anywhere from a 10th of a second to very close to a full second; this is regardless of whether or not the track is gapless. In a gapless album, there will be an additional "tick" at the start of the next track (this I can live with!).
95% of my tracks are FLAC. Some are high definition, most are 16/44.1, and the problem occurs regardless of the compression format. Also, I have tried with all three transcoding choices, and with no transcoding. I have deleted the and reinstalled the app, restarted my computer and router, deleted old DLNA servers and added the generic one (voodoo science, but why not!) all to no avail ...