no sound and no errors on 8.10!

I'm under Ubuntu 8.10,
on a laptop hp 6730b (intel centrino 2 version).
I have no sound on the gnome desktop neither any application.
I checked the gnome volume control applet to see if some lines were mute.
I also checked the alsamixer in text mode to be sure.

I don't have any idea anymore where to search to solve the problem but I can give some hints : kernel modules seem to be loaded correctly :

lspci -vvs 00:1b.0
00:1b.0 Audio device: Intel Corporation 82801I (ICH9 Family) HD Audio Controller (rev 03)
 Subsystem: Hewlett-Packard Company Device 30e6
 Control: I/O- Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B- DisINTx-
 Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx-
 Latency: 0, Cache Line Size: 64 bytes
 Interrupt: pin A routed to IRQ 17
 Region 0: Memory at 98900000 (64-bit, non-prefetchable) [size=16K]
 Capabilities: [50] Power Management version 2
  Flags: PMEClk- DSI- D1- D2- AuxCurrent=55mA PME(D0+,D1-,D2-,D3hot+,D3cold+)
  Status: D0 PME-Enable- DSel=0 DScale=0 PME-
 Capabilities: [60] Message Signalled Interrupts: Mask- 64bit+ Queue=0/0 Enable-
  Address: 0000000000000000 Data: 0000
 Capabilities: [70] Express (v1) Root Complex Integrated Endpoint, MSI 00
  DevCap: MaxPayload 128 bytes, PhantFunc 0, Latency L0s <64ns, L1 <1us
   ExtTag- RBE- FLReset+
  DevCtl: Report errors: Correctable- Non-Fatal- Fatal- Unsupported-
   RlxdOrd- ExtTag- PhantFunc- AuxPwr- NoSnoop+
   MaxPayload 128 bytes, MaxReadReq 128 bytes
  DevSta: CorrErr- UncorrErr- FatalErr- UnsuppReq- AuxPwr+ TransPend-
  LnkCap: Port #0, Speed unknown, Width x0, ASPM unknown, Latency L0 <64ns, L1 <1us
   ClockPM- Suprise- LLActRep- BwNot-
  LnkCtl: ASPM Disabled; Disabled- Retrain- CommClk-
   ExtSynch- ClockPM- AutWidDis- BWInt- AutBWInt-
  LnkSta: Speed unknown, Width x0, TrErr- Train- SlotClk- DLActive- BWMgmt- ABWMgmt-
 Capabilities: [100] Virtual Channel <?>
 Capabilities: [130] Root Complex Link <?>
 Kernel driver in use: HDA Intel
 Kernel modules: snd-hda-intel

------------------------

 lsmod | grep snd
snd_hda_intel 381488 3
snd_pcm_oss 46848 0
snd_mixer_oss 22784 1 snd_pcm_oss
snd_pcm 83204 2 snd_hda_intel,snd_pcm_oss
snd_seq_dummy 10884 0
snd_seq_oss 38528 0
snd_seq_midi 14336 0
snd_rawmidi 29824 1 snd_seq_midi
snd_seq_midi_event 15232 2 snd_seq_oss,snd_seq_midi
snd_seq 57776 6 snd_seq_dummy,snd_seq_oss,snd_seq_midi,snd_seq_midi_event
snd_timer 29960 2 snd_pcm,snd_seq
snd_seq_device 15116 5 snd_seq_dummy,snd_seq_oss,snd_seq_midi,snd_rawmidi,snd_seq
snd 63268 15 snd_hda_intel,snd_pcm_oss,snd_mixer_oss,snd_pcm,snd_seq_oss,snd_rawmidi,snd_seq,snd_timer,snd_seq_device
soundcore 15328 1 snd
snd_page_alloc 16136 2 snd_hda_intel,snd_pcm