Lost lots of volume suddenly - help?!

[Julian Gilbey <jdg@polya.uklinux.net>]

Any suggestions on this one: I'm running ALSA (with ESD) and between
turning my computer off yesterday and switching it on today, the
output volume has been decimated.  I need to change the master volume
and program output volume (in eg, xmms, alsaplayer) to close to 100%
to hear anything, and then it starts squealing.

I've checked the hardware - nothing obvious, and Windows (dual-boot
machine) still seems to work fine, so I'm suspecting some software
setting.

I'm running testing (etch); any suggestions please?

Thanks!

   Julian