I've been running into the same issue with my Dell Inspiron 640m laptop.
$ uname -a Linux felix 2.6.24-19-generic #1 SMP Fri Jul 11 23:41:49 UTC 2008 i686 GNU/Linux
$ lsmod | grep snd snd_hda_intel 344728 4 snd_pcm_oss 42144 0 snd_mixer_oss 17920 1 snd_pcm_oss snd_pcm 78596 2 snd_hda_intel,snd_pcm_oss snd_page_alloc 11400 2 snd_hda_intel,snd_pcm snd_hwdep 10500 1 snd_hda_intel snd_seq_dummy 4868 0 snd_seq_oss 35584 0 snd_seq_midi 9376 0 snd_rawmidi 25760 1 snd_seq_midi snd_seq_midi_event 8320 2 snd_seq_oss,snd_seq_midi snd_seq 54224 6 snd_seq_dummy,snd_seq_oss,snd_seq_midi,snd_seq_midi_event snd_timer 24836 2 snd_pcm,snd_seq snd_seq_device 9612 5 snd_seq_dummy,snd_seq_oss,snd_seq_midi,snd_rawmidi,snd_seq snd 56996 19 snd_hda_intel,snd_pcm_oss,snd_mixer_oss,snd_pcm,snd_hwdep,snd_seq_dummy,snd_seq_oss,snd_rawmidi,snd_seq,snd_timer,snd_seq_device soundcore 8800 1 snd
I've been running into the same issue with my Dell Inspiron 640m laptop.
$ uname -a
Linux felix 2.6.24-19-generic #1 SMP Fri Jul 11 23:41:49 UTC 2008 i686 GNU/Linux
$ lsmod | grep snd intel,snd_ pcm_oss intel,snd_ pcm oss,snd_ seq_midi dummy,snd_ seq_oss, snd_seq_ midi,snd_ seq_midi_ event dummy,snd_ seq_oss, snd_seq_ midi,snd_ rawmidi, snd_seq intel,snd_ pcm_oss, snd_mixer_ oss,snd_ pcm,snd_ hwdep,snd_ seq_dummy, snd_seq_ oss,snd_ rawmidi, snd_seq, snd_timer, snd_seq_ device
snd_hda_intel 344728 4
snd_pcm_oss 42144 0
snd_mixer_oss 17920 1 snd_pcm_oss
snd_pcm 78596 2 snd_hda_
snd_page_alloc 11400 2 snd_hda_
snd_hwdep 10500 1 snd_hda_intel
snd_seq_dummy 4868 0
snd_seq_oss 35584 0
snd_seq_midi 9376 0
snd_rawmidi 25760 1 snd_seq_midi
snd_seq_midi_event 8320 2 snd_seq_
snd_seq 54224 6 snd_seq_
snd_timer 24836 2 snd_pcm,snd_seq
snd_seq_device 9612 5 snd_seq_
snd 56996 19 snd_hda_
soundcore 8800 1 snd