Bug or not? Problems with 5.1 analogue audio otput (1 Viewer)

[mamachan]

MediaPortal Version: 1.1. b1
MediaPortal Skin: Black Glass
Windows Version: XP Pro sp.3
CPU Type: Intel Core 2 Duo E6400
HDD: Samsung 1x250gb + 2x500GB
Memory: Corsair 2x1024
Motherboard: Asus P5B Deluxe Wifi AP
Video Card: ATI HD3470
Video Card Driver: Catalyst 9.4
Sound Card: Club3d Theatron Agrippa DTS 7.1
Sound Card AC3: S/PDIF optical out
Sound Card Driver:
1. TV Card: TT S2-3200
1. TV Card Type: DVB-S2
1. TV Card Driver: 5.0.0.19
2. TV Card: Floppy DTV T/CI
2. TV Card Type: DVB-T CI
2. TV Card Driver: Latest
3. TV Card:
3. TV Card Type:
3. TV Card Driver:
4. TV Card:
4. TV Card Type:
4. TV Card Driver:
MPEG2 Video Codec: ffdshow
MPEG2 Audio Codec: ffdshow
h.264 Video Codec: Cyberlink H.264
Satelite/CableTV Provider:
HTPC Case: Lian Li PC-C33
Cooling:
Power Supply: LC Power 550W
Remote: MCE Remote
TV: Samsung Plasma PS42A456
TV - HTPC Connection: DVI

Goodmorning.
I don't know if it is a bug or only a my problem.
I connect the HTPC to the A/V reciver by 5.1 analogue cable (minijack/RCA stereo).
But if i use BASS Player or PureAudio, ALL music files (2CH stereo too) are upmixed in 5.1 (i don't like this).
If i use Internal dshow player (instead BASS or PureAudio) and set "Default DirectSound Device" (with BASS is not possible to set Default DirectSound Device) ALL works fine (stereo like stereo, multichannel like multichannel).
In this way Mediaportal use (on my system) ffdshow audio decoder for ALL music files in the correctly mode.

Is normal?

Thanks
Regards
mamachan

NB: I started the topic here https://forum.team-mediaportal.com/...ugin-problem-5-1-analogue-audio-output-82570/ , but i thinks music section is good choice.