link error in mplayer - no 5.1 audio played

[udippel]

Since my upgrade yesterday, it doesn't play 5.1 any longer, but 'mirrors' everything to the front.
Sytem Settings->Multimedia->Phonon->Audio Hardware Setup shows the 'Speaker Placement and Testing', and when I click on the locations, all do a great job. Mplayer however doesn't. And there are some good (?) reasons:

$ mplayer media/musics/6_Channel_ID.wav
mplayer: Symbol `ff_codec_bmp_tags' has different size in shared object, consider re-linking
MPlayer SVN-r33713-4.6.1 (C) 2000-2011 MPlayer Team
mplayer: could not connect to socket
mplayer: No such file or directory
Failed to open LIRC support. You will not be able to use your remote control.

Playing media/musics/6_Channel_ID.wav.
Audio only file format detected.
Load subtitles in media/musics/
==========================================================================
Opening audio decoder: [pcm] Uncompressed PCM audio decoder
AUDIO: 44100 Hz, 6 ch, s16le, 4233.6 kbit/100.00% (ratio: 529200->529200)
Selected audio codec: [pcm] afm: pcm (Uncompressed PCM)
==========================================================================
AO: [pulse] 44100Hz 2ch floatle (4 bytes per sample)
Video: no video
Starting playback...
A: 5.5 (05.5) of 5.0 (05.0) 0.7%

As you can see, the AO is pulse, but 2ch; whereas the file has been identified as 44100 Hz, 6 ch
On 11.04 this latter was not the case.

I have selected the medibuntu repository for oneiric, and uninstalled/reinstalled mplayer. A search on Google revealed a similar case earlier this year in Debian:
http://linuxindetails.wordpress.com/tag/mplayer-symbol-ff_codec_bmp_tags-has-different-size-in-shared-object/

ProblemType: Bug
DistroRelease: Ubuntu 11.10
Package: mplayer 2:1.0~rc4.dfsg1+svn33713-1+medibuntu1
ProcVersionSignature: Ubuntu 3.0.0-12.20-generic 3.0.4
Uname: Linux 3.0.0-12-generic x86_64
NonfreeKernelModules: nvidia
ApportVersion: 1.23-0ubuntu3
Architecture: amd64
CrashDB: medibuntu
Date: Sat Oct 15 23:09:33 2011
InstallationMedia: Kubuntu 10.04 LTS "Lucid Lynx" - Release amd64 (20100427)
ProcEnviron:
 LANGUAGE=
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: mplayer
UpgradeStatus: Upgraded to oneiric on 2011-10-14 (1 days ago)