"force_hdmi_open=1" in config.txt file is the base answer
Well after nearly a year trying to make XBMC play a clasical/opera CDs (made of multiple tracks/files)
and any other CD or track without dropping the first ~2nd of audio I found the above worked for me.
The problem is that my amp would see the "gap" in the HDMI stream between tracks and resync, I have also
heard lots of others having similar problems in high end AMPS using RPI to deliver HiFi over HDMI.
"popcornmix" from openelec Raspberry PI test forums suggested this when I asked/begged if we new of anything to help...
I will ask him to added it to the config file and document it there.
I can not find a reference to this option on any of the offical RPI forums or sites!
so in summary OpenElec 3.1.6, with the option above added to the config.txt file gives my a first class xbmc audio jukebox with gapless (near enought) play back to my Yamha amp. Way to go.