Why DTS-HD Master Audio 7.1 become DTS-ES Matrix 6.1?

[outcave]

Hi guys.
If I play a mkv file with audio DTS-HD Master Audio 7.1 with UMS 2.0 and PS3, the audio will be DTS-ES Matrix 6.1.
Why?

Equipment:
UMS 2.0 using MEncoder and "keep DTS track" enabled
PS3
ONKYO TX-NR509 amplifier
1Gbit link beetwen PS3 and PC

[SubJunk]

Hi outcave, please post your debug information

[outcave]

Hi,
in attach the debug.log (but I cannot see any info about DTS, I see only LPCM...).
This is the Audio track info of the mkv file (taken from MediaInfo):

Audio #3
ID : 4
Format : DTS
Format/Info : Digital Theater Systems
Format profile : MA / Core
Mode : 16
Format settings, Endianness : Big
Codec ID : A_DTS
Duration : 1h 27mn
Bit rate mode : Variable
Bit rate : Unknown / 1 509 Kbps
Channel(s) : 8 channels / 6 channels
Channel positions : Front: L C R, Side: L R, Back: L R, LFE / Front: L C R, Side: L R, LFE
Sampling rate : 48.0 KHz
Bit depth : 24 bits
Compression mode : Lossless / Lossy
Title : English DTS-HD MA 7.1
Language : English
Default : No
Forced : No


Thanks and let me know.