Rear channels on AAC 5.1 are not played properly w/ LPCM 5.1 out

Rear channels dont put out 5.1 sound. This was also the case when the box just came out, and was resolved with ticket BOXEE-7081. However, since the last couple of updates, the problem is back: only the front speakers produce sound with AAC-codec video-files...

MediaInfo file:

General
Complete name : \\DS210J\video\blu-ray\***.mp4
Format : MPEG-4
Format profile : Base Media
Codec ID : isom
File size : 2.40 GiB
Duration : 2h 10mn
Overall bit rate mode : Variable
Overall bit rate : 2 634 Kbps
Encoded date : UTC 2011-08-18 09:37:28
Tagged date : UTC 2011-08-18 09:37:28

Video
ID : 1
Format : AVC
Format/Info : Advanced Video Codec
Format profile : High@L5.1
Format settings, CABAC : Yes
Format settings, ReFrames : 5 frames
Codec ID : avc1
Codec ID/Info : Advanced Video Coding
Duration : 2h 10mn
Source duration : 1mn 30s
Bit rate : 2 185 Kbps
Maximum bit rate : 18.1 Mbps
Width : 1 280 pixels
Height : 544 pixels
Display aspect ratio : 2.35:1
Frame rate mode : Constant
Frame rate : 23.976 fps
Color space : YUV
Chroma subsampling : 4:2:0
Bit depth : 8 bits
Scan type : Progressive
Bits/(Pixel*Frame) : 0.131
Stream size : 1.99 GiB (83%)
Source stream size : 1.99 GiB
Writing library : x264 core 80 r1376M 3feaec2
Encoding settings : cabac=1 / ref=5 / deblock=1:0:0 / analyse=0x3:0x113 / me=umh / subme=8 / psy=1 / psy_rd=1.0:0.0 / mixed_ref=1 / me_range=16 / chroma_me=1 / trellis=1 / 8x8dct=1 / cqm=0 / deadzone=21,11 / fast_pskip=1 / chroma_qp_offset=0 / threads=12 / sliced_threads=0 / nr=0 / decimate=1 / mbaff=0 / constrained_intra=0 / bframes=3 / b_pyramid=0 / b_adapt=2 / b_bias=0 / direct=3 / wpredb=1 / wpredp=2 / keyint=250 / keyint_min=25 / scenecut=40 / rc_lookahead=50 / rc=2pass / mbtree=1 / bitrate=2185 / ratetol=1.0 / qcomp=0.60 / qpmin=10 / qpmax=51 / qpstep=4 / cplxblur=20.0 / qblur=0.5 / ip_ratio=1.40 / aq=1:1.00
Encoded date : UTC 2011-08-18 04:04:19
Tagged date : UTC 2011-08-18 09:39:52

Audio
ID : 2
Format : AAC
Format/Info : Advanced Audio Codec
Format profile : LC
Codec ID : 40
Duration : 2h 10mn
Bit rate mode : Variable
Bit rate : 445 Kbps
Maximum bit rate : 644 Kbps
Channel(s) : 6 channels
Channel positions : Front: L C R, Side: L R, LFE
Sampling rate : 48.0 KHz
Compression mode : Lossy
Stream size : 415 MiB (17%)
Title : Imported with GPAC 0.4.6-DEV (build 1)
Encoded date : UTC 2011-08-18 09:38:55
Tagged date : UTC 2011-08-18 09:39:52