OK so I have installed kphone which apparently only uses OSS, and after fiddling around with the volume settings I even got it to work. However when I reboot the machine, the OSS settings go back to their defaults.

I then installed oss-preserve, which is supposed to save my OSS mixer settings. Pity there aren't any instructions for using it. Anyway I tried running oss-preserve start/restart/force-reload, and all it seems to do is restore the default settings, which is the exact opposite of what I was hoping for.

Don't know if it's relevant, but I got a nice warning message too, eg:

/etc/init.d/oss-preserve restart
Saving OSS mixer settings...
** WARNING **: Mismatch between OSS version of program and kernel.
The program was compiled with version 0x030802,
but the kernel implements version 0x030810.
done.
Restoring OSS mixer settings...done.

By the way I'm using Ubuntu 4.10. Surely this should be perfectly simple...but... how can I save my volume settings?

Aha I've got it now...

System -> Preferences -> Sessions -> Automatically save changes to session

did the trick. Oh and I had to apt-get remove oss-preserve as well.