Soundcard not detected, although previously ok

[philip <philip@striplin.co.uk>]

I'm running Debian Sarge with 2.6.8 kernel.  There are two sound devices 
attached, the onboard Realtek chip and a TV card.

Until this week, both were detected OK.  I had to put an explicit line 
in /etc/modprobe.d/sound

options snd-via82xx index=0
options snd-bt87x index=1

to ensure that the Realtek is treated as the default (otherwise I had to 
run alsaconf every boot to force it to treat the realtek as default).  
With those lines in place, Alsamixer would then work with the Realtek 
chip (and so would everything else).

However, this no longer works.  If run manually, alsaconf seems to 
detect the card OK, but doesn't write anything about the card into 
modules.conf or anywhere else that I can see.  Alsamixer only sees the 
bt87x, which is not a lot of use.  KDE has reverted to "device not 
found" message.

I've been taking the updates fairly regularly, but I'm not aware of 
anything else that has changed.  Sound still behaves fine if I boot the 
machine in Windows XP, so the chip itself seems fine.

Any ideas about how to go about diagnosing what's gone wrong this time?

Thanks

Phil