Yes mate it would appear it's your player. I downloaded the manual for LGBD590 and the audio listing is
Playable Audio format: “Dolby Digital”, “DTS”,
“MP3”, “WMA”, “AAC”, “AC3”
Not all the WMA and AAC Audio format are
compatible with this unit.
No mention of DTSMA. I use a WDTV Live media player at present and while it will pass through the DTS core it won't play DTSMA. I am waiting on a new DUNE Smart H1 which apparently handles all Audio.
Any way sounds like the problem is hardware not software