"Front" alsa control is turned off by PulseAudio for "Analog Headphones" profile

Hi Petter and thanks for reporting this bug!
The problem is inconsistent naming of volume controls - on some machines, such as yours, the "Front" volume control is part of what's controlling the headphone volume, but on most machines, it isn't. So PulseAudio can't know - based on the name - whether to use the "front" volume control or turn it off. Current behaviour is to turn it off, but I've been thinking about whether setting it to zero would be better.

In your case you actually have a "virtual" master control so you would get the same sound quality as if you were able to control "Front".

This will be applied the next time Pulseaudio is released into Oneiric. Meanwhile, you can try editing /usr/share/pulseaudio/alsa-mixer/paths/analog-output-headphones.conf and change

 [Element Front]
switch = off
volume = off

to

 [Element Front]
switch = mute
volume = zero

This bug was fixed in the package pulseaudio - 1:0.99.3-0ubuntu1

---------------
pulseaudio (1:0.99.3-0ubuntu1) oneiric; urgency=low

  [ David Henningsson ]
  * 0018-alsa-mixer-Set-Front-control-to-0-dB-on-headphone-pa.patch:
    Set Front to 0 dB for Headphones (LP: #836921)

  [ Luke Yelavich ]
  * New upstream bugfix release
    - source: Remove the PA_SOURCE_PASSTHROUGH flag
    - alsa: Don't always suspend/unsuspend on sink-input removal
    - formats: Use correct API to check for passthrough streams
    - alsa: Open iec958 device with NONAUDIO bit set in passthrough mode
    - formats: Fix bad passsthrough check
    - alsa: Fix bad function name
    - daemon: Fix compiler warning about missing function prototype
    - passthrough: We must not plug in a resampler on stream move
    - sink-input: Ensure no volumes are applied for passthrough streams
    - source-output: Ensure no volumes are applied for passthrough streams
    - Revert "device-restore: Make bools not be bit fields"
    - sample-util: Fix off-by-one in error check
    - sink: Add PA_SINK_SET_FORMATS macro
    - build-sys: Fix some LDFLAGS vs. LDADD usage
    - echo-cancel: Add multiple include protection for header
    - echo-cancel: Use pa_streq instead of strcmp
    - echo-cancel: Move speex preprocessing out of the main module
    - passthrough: Fix what volume we set sinks/sources to
    - passthrough: Fix setting volume to unamplified again
    - echo-cancel: Make save_aec modarg a bool instead of an int
    - echo-cancel: Don't allow streams to attach while unloading
    - echo-cancel: Get rid of annoying compiler warnings
    - equalizer: Comment out unused function
    - def: Add a new enum to allow differntiation between sinks and sources.
    - dbus: Use pa_device_type_t rather than an internal equivalent
    - device-restore: Change the API to include type information (sink
      vs. source)
    - device-restore: Split device restore database into two parts.
    - device-restore: Restore volumes on port change.
    - build-sys: bump soname
    - alsa-mixer: Mute IEC958 optical raw for several Audigy models
    - alsa-mixer: Add "Line HP Swap" element
    - JACK: Load module-jackdbus-detect in default.pa
    - Remove offensive part of error message
    - switch-on-connect: Don't switch to a monitor source
    - Fix spelling sucess -> success
    - Set better priorities on input paths
    - introspect: fix typo in default sink/source docs
    - pacat: make pacat respond to cork/uncork events
    - Spelling fixes in public headers
    - More spelling fixes
    - gitignore: Add Orc autogenerated files
    - echo-cancel: Use stream index in debug message
    - Remove extra ; s where they are not allowed in strict C99
    - sndfile-util: Check return value of sf_command for errors
  * Pull some further fixes from upstream git master:
    - fb107fc (vala: Add has_type_id=false to all enums, structs and classes)
    - c7bba24 (module-switch-on-connect: Don't switch unlinked sink input and
               source outputs)
    - 9636991 (alsa-mixer: Set "Front" control to 0 dB on headphone path)
    - fc3ddfb (module-equalizer-sink: Use %z for printf of size_t variables)
...