Hey,
I am using a similar setup. uname -a displays:
Linux main 2.6.13 #1 Sat Sep 3 15:44:55 MDT 2005 x86_64 AMD Athlon(tm) 64 Processor 3000+ AuthenticAMD GNU/Linux
I've recompiled the kernel to latest stable release on
www.kernel.org. If I do lspci it gives me the following audio info:
00:11.5 Multimedia audio controller: VIA Technologies, Inc. VT8233/A/8235/8237 AC97 Audio Controller (rev 60)
So I have a different chipset than you, but I was having weird problems as well when trying to use modules with my sound configuration, so I configured all the sound stuff to be compiled with the kernel. It has worked for me on 2 boxes so far and has never cut out on me.
I also use the alsa sound stuff instead of the OSS stuff. Here is the sound configuration in my kernel config:
#
# Sound
#
CONFIG_SOUND=y
#
# Advanced Linux Sound Architecture
#
CONFIG_SND=y
CONFIG_SND_TIMER=y
CONFIG_SND_PCM=y
CONFIG_SND_RAWMIDI=y
CONFIG_SND_SEQUENCER=y
# CONFIG_SND_SEQ_DUMMY is not set
CONFIG_SND_OSSEMUL=y
CONFIG_SND_MIXER_OSS=y
CONFIG_SND_PCM_OSS=y
# CONFIG_SND_SEQUENCER_OSS is not set
# CONFIG_SND_RTCTIMER is not set
# CONFIG_SND_VERBOSE_PRINTK is not set
# CONFIG_SND_DEBUG is not set
#
# Generic devices
#
CONFIG_SND_MPU401_UART=y
# CONFIG_SND_DUMMY is not set
# CONFIG_SND_VIRMIDI is not set
# CONFIG_SND_MTPAV is not set
# CONFIG_SND_SERIAL_U16550 is not set
# CONFIG_SND_MPU401 is not set
#
# PCI devices
#
CONFIG_SND_AC97_CODEC=y
# CONFIG_SND_ALI5451 is not set
# CONFIG_SND_ATIIXP is not set
# CONFIG_SND_ATIIXP_MODEM is not set
# CONFIG_SND_AU8810 is not set
... (whole bunch of sound chipsets) ...
# CONFIG_SND_INTEL8X0M is not set
# CONFIG_SND_SONICVIBES is not set
CONFIG_SND_VIA82XX=y
# CONFIG_SND_VIA82XX_MODEM is not set
# CONFIG_SND_VX222 is not set
# CONFIG_SND_HDA_INTEL is not set
After compiling the kernel and rebooting, I just ran alsamixer and unmuted the master volume and the pcm volume and everything worked. It's possible you may need to run alsaconf before alsamixer, but I did not have to since there were no modules to mess with.
Good luck.