Trying to use a plantronics 510s with skype.

Update on my attempts, I've established the setup that almost works. By 
almost works I mean:
- aplay, arecord -D headset work, quality is fine for telephone use.
- aoss skype almost works: I can hear the test call clearly, I can 
record a message but when it is played back my voice is garbled beyond 
recognition.

My next step is to fiddle with pcm settings - I've seen .asoundrc 
scripts for skype and dmix that do conversions between 8 and 16 bit 
formats and other stuff I know nothing about (but am afraid I'm gonna 
learn). Here are the details of how I got this far:

== DETAILS: based on btsco/docs/build.html from CVS, slightly modified.

install libsbc:

Note: When asking for a password simply press Enter.

cvs -d:pserver:anonymous@sbc.cvs.sourceforge.net:/cvsroot/sbc login
cvs -d:pserver:anonymous@sbc.cvs.sourceforge.net:/cvsroot/sbc co sbc
cd sbc
./bootstrap
./configure --prefix=/usr
make
sudo make install

install bstco:

cvs 
-d:pserver:anonymous@bluetooth-alsa.cvs.sourceforge.net:/cvsroot/bluetooth-alsa 
login
cvs 
-d:pserver:anonymous@bluetooth-alsa.cvs.sourceforge.net:/cvsroot/bluetooth-alsa 
co btsco
cd btsco
./bootstrap
# Note I added CFLAGS in ./configure. Without them the plugin emits
# a torrent of debug messages that slow it down and ruin the sound quality.
# -NDEBUG is essential, -03 is just for good luck.
./configure --prefix=/usr --enable-alsaplugin CFLAGS="-NDEBUG -03"
make
sudo make install

** Using from skype
My .asoundrc is copied from btsco/alsa-plugins/asound.conf with the
headset address replaced by my own and the following addition for aoss:

# Use headset via aoss emulation for skype.

pcm.dsp0 {
   type plug
   slave.pcm "hw_headset"     
}

Full .asoundrc attached. Run skype as "aoss skype" (you need alsa-oss 
package installed.)


== NOTES

The instructions at http://bluetooth-alsa.sourceforge.net/build.html did 
*not* work for me. The plugz version of the plugin requires a different 
.asoundrc (based on plugz/asound.conf) but aplay -D headset gave me:

[aconway@scooter plugz]$ aplay -D headset /usr/share/sounds/startup3.wav
Playing WAVE '/usr/share/sounds/startup3.wav' : Signed 16 bit Little 
Endian, Rate 44100 Hz, Stereo
aplay: set_params:909: Channels count non available

Cheers,
Alan.