update to latest etch caused multiple problems - can't boot, no sound

["John Lee" <john@reonsoft.com>]

first of all I cannot boot after update.  traced and find out some
strange problems:

1. sd_mod won't load.  my system is running on SATA so mdadm will fail
to assemble my (/home) md0.  also the system will not be able to mount
(/root) /dev/sda1 since all /dev/sda* were not there.

2. change grub option to use initrd.img-2.6.18-4-686.bak instead, the
system boots fine, but the sound stops working.

# lsmod | grep snd
snd_intel8x0           30332  0
snd_ac97_codec         83104  1 snd_intel8x0
snd_ac97_bus            2400  1 snd_ac97_codec
snd_pcm_oss            38368  0
snd_mixer_oss          15200  1 snd_pcm_oss
snd_pcm                68676  3 snd_intel8x0,snd_ac97_codec,snd_pcm_oss
snd_timer              20996  1 snd_pcm
snd                    47012  6
snd_intel8x0,snd_ac97_codec,snd_pcm_oss,snd_mixer_oss,snd_pcm,snd_timer
soundcore               9248  1 snd
snd_page_alloc          9640  2 snd_intel8x0,snd_pcm

#ls /dev/snd
total 0
crw-rw---- 1 root audio 116, 33 2007-03-30 01:31 timer

# ls /dev/dsp
ls: /dev/dsp: No such file or directory

# cat /proc/asound/cards
0 [SI7012         ]: ICH - SiS SI7012
                     SiS SI7012 with ALC655 at 0xe000, irq 10

# cat /proc/asound/devices
 0: [ 0]   : control
16: [ 0- 0]: digital audio playback
24: [ 0- 0]: digital audio capture
25: [ 0- 1]: digital audio capture
33:        : timer

# amixer
amixer: Mixer attach default error: No such device

# amixer -c 0
Invalid card number.

alsaconf won't help either.  any idea will be most appreciated.  thanks.

-- John