troubleshooting sound problems

[Tomoki Taniguchi]

I need help getting my sound card working on my laptop.
the sound card was working under windows prior to installing gutsy,
so i know the hardware works.

"aplay -l" gives me
**** List of PLAYBACK Hardware Devices ****
card 0: I82801DBICH4 [Intel 82801DB-ICH4], device 0: Intel ICH [Intel
82801DB-ICH4]
  Subdevices: 0/1
  Subdevice #0: subdevice #0
card 0: I82801DBICH4 [Intel 82801DB-ICH4], device 4: Intel ICH -
IEC958 [Intel 82801DB-ICH4 - IEC958]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 1: Modem [Intel 82801DB-ICH4 Modem], device 0: Intel ICH - Modem
[Intel 82801DB-ICH4 Modem - Modem]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
so it seems the sound card is recognized.

i've checked alsamixer to make sure all the settings are unmuted.

but i still get no sound when i play an mp3 or a video file.

is there anything else i can try?

TIA,
Tomoki