Mplayer errors since Pulseaudio upgrade

Question

Hey all... wondering if anyone has seen this problem yet... I've searched high & low but I've not been able to find any bugs raised in the mplayer project or any recent posts in here...
Since upgrading pulseaudio from version 5 to version 6, mplayer has stopped playing any videos in 6 channel surround sound using pulse.  I initially though it was pulseaudios fault, I downgraded & mplayer worked again... but I upgraded again &  tested with VLC & a host of different apps, VLC is outputting surround sound via pulse and everything else works fine. 
Mplayer works except when using the switch "-channels 6"
I can play any movie using mplayer in stereo using:  mplayer -ao pulse -channels 2 somefile but mplayer -ao pulse -channels 6 somefile fails with the below AO: [pulse] pa_stream_write() failed: Invalid argument errors in the log which just keep repeating and the video shows as frozen on the screen.
==========================================================================
Forced video codec: ffh264vdpau
Opening video decoder: [ffmpeg] FFmpeg's libavcodec codec family
libavcodec version 56.13.100 (internal)
Selected video codec: [ffh264vdpau] vfm: ffmpeg (FFmpeg H.264 (VDPAU))
==========================================================================
ID_VIDEO_CODEC=ffh264vdpau
==========================================================================
Opening audio decoder: [ffmpeg] FFmpeg/libavcodec audio decoders
AUDIO: 48000 Hz, 6 ch, floatle, 384.0 kbit/4.17% (ratio: 48000->1152000)
ID_AUDIO_BITRATE=384000
ID_AUDIO_RATE=48000
ID_AUDIO_NCH=6
Selected audio codec: [ffac3] afm: ffmpeg (FFmpeg AC-3)
==========================================================================
AO: [pulse] 48000Hz 6ch floatle (4 bytes per sample)
ID_AUDIO_CODEC=ffac3
[Mixer] No hardware mixing, inserting volume filter.
Starting playback...
AO: [pulse] pa_stream_write() failed: Invalid argument
AO: [pulse] pa_stream_write() failed: Invalid argument
AO: [pulse] pa_stream_write() failed: Invalid argument
Movie-Aspect is 2.40:1 - prescaling to correct movie aspect.
ID_VIDEO_ASPECT=2.4020
VO: [vdpau] 1912x796 => 1912x796 H.264 VDPAU acceleration
Movie-Aspect is 2.40:1 - prescaling to correct movie aspect.
ID_VIDEO_ASPECT=2.4020
VO: [vdpau] 1912x796 => 1912x796 H.264 VDPAU acceleration
[ass] PlayResX undefined, setting to 384
AO: [pulse] pa_stream_write() failed: Invalid argument
AO: [pulse] pa_stream_write() failed: Invalid argument
AO: [pulse] pa_stream_write() failed: Invalid argument
AO: [pulse] pa_stream_write() failed: Invalid argument
AO: [pulse] pa_stream_write() failed: Invalid argument
AO: [pulse] pa_stream_write() failed: Invalid argument
AO: [pulse] pa_stream_write() failed: Invalid argument
AO: [pulse] pa_stream_write() failed: Invalid argument
AO: [pulse] pa_stream_write() failed: Invalid argument
AO: [pulse] pa_stream_write() failed: Invalid argument
AO: [pulse] pa_stream_write() failed: Invalid argument
AO: [pulse] pa_stream_write() failed: Invalid argument

Answer 1

Same problem here. For "mplayer -ao X..." and X>2, i get this:
MPlayer SVN-r37353 (C) 2000-2015 MPlayer Team
210 audio & 441 video codecs
do_connect: could not connect to socket
connect: No such file or directory
Failed to open LIRC support. You will not be able to use your remote control.
Playing ************************************.mkv.
libavformat version 56.15.102 (internal)
libavformat file format detected.
[lavf] stream 0: video (h264), -vid 0
[lavf] stream 1: audio (ac3), -aid 0, -alang eng
VIDEO:  [H264]  1280x532  0bpp  23.976 fps    0.0 kbps ( 0.0 kbyte/s)
Clip info:
encoder: libebml v1.2.3 + libmatroska v1.3.0
creation_time: 2012-12-21 00:20:30
Load subtitles in ./
SUB: Added subtitle file (1): ./************************************.srt
==========================================================================
Opening video decoder: [ffmpeg] FFmpeg's libavcodec codec family
libavcodec version 56.13.100 (internal)
Selected video codec: [ffh264] vfm: ffmpeg (FFmpeg H.264)
==========================================================================
==========================================================================
Opening audio decoder: [ffmpeg] FFmpeg/libavcodec audio decoders
AUDIO: 48000 Hz, 6 ch, floatle, 448.0 kbit/4.86% (ratio: 56000->1152000)
Selected audio codec: [ffac3] afm: ffmpeg (FFmpeg AC-3)
==========================================================================
AO: [pulse] 48000Hz 6ch floatle (4 bytes per sample)
Starting playback...
AO: [pulse] pa_stream_write() failed: Invalid argument
AO: [pulse] pa_stream_write() failed: Invalid argument
AO: [pulse] pa_stream_write() failed: Invalid argument
Movie-Aspect is 2.41:1 - prescaling to correct movie aspect.
VO: [vdpau] 1280x532 => 1280x532 Planar YV12
A:   0.0 V:   0.0 A-V:  0.000 ct:  0.000   0/  0 ??% ??% ??,?% 0 0
AO: [pulse] pa_stream_write() failed: Invalid argument
AO: [pulse] pa_stream_write() failed: Invalid argument
AO: [pulse] pa_stream_write() failed: Invalid argument
A:   0.0 V:   0.0 A-V: -0.042 ct:  0.000   0/  0 ??% ??% ??,?% 0 0
AO: [pulse] pa_stream_write() failed: Invalid argument
AO: [pulse] pa_stream_write() failed: Invalid argument
AO: [pulse] pa_stream_write() failed: Invalid argument
A:   0.0 V:   0.0 A-V: -0.042 ct:  0.000   0/  0 ??% ??% ??,?% 0 0
AO: [pulse] pa_stream_write() failed: Invalid argument
AO: [pulse] pa_stream_write() failed: Invalid argument
AO: [pulse] pa_stream_write() failed: Invalid argument
A:   0.0 V:   0.0 A-V: -0.042 ct:  0.000   0/  0 ??% ??% ??,?% 0 0
AO: [pulse] pa_stream_write() failed: Invalid argument
AO: [pulse] pa_stream_write() failed: Invalid argument
AO: [pulse] pa_stream_write() failed: Invalid argument
A:   0.0 V:   0.0 A-V: -0.042 ct:  0.000   0/  0 ??% ??% ??,?% 0 0
AO: [pulse] pa_stream_write() failed: Invalid argument
AO: [pulse] pa_stream_write() failed: Invalid argument
AO: [pulse] pa_stream_write() failed: Invalid argument
A:   0.0 V:   0.0 A-V: -0.042 ct:  0.000   0/  0 ??% ??% ??,?% 0 0
AO: [pulse] pa_stream_write() failed: Invalid argument
AO: [pulse] pa_stream_write() failed: Invalid argument
AO: [pulse] pa_stream_write() failed: Invalid argument
A:   0.0 V:   0.0 A-V: -0.042 ct:  0.000   0/  0 ??% ??% ??,?% 0 0
AO: [pulse] pa_stream_write() failed: Invalid argument
AO: [pulse] pa_stream_write() failed: Invalid argument
AO: [pulse] pa_stream_write() failed: Invalid argument