Need to reconfigure the sound

Hello, i'm currently using Ubuntu Intrepid Ibex (32 bits) in my HP DV2840SE laptop.
Everything was working awesome, auto detected perfectly and stuff.

Then, all the sudden, after some reboot, my sound system stopped working. I mean, the card is still correctly detected, alsa is working, mixer is working (is detecting the different channels, i can change their volume, etc) but when i try to play some music or reproduce whatever sound i hear a garbled sound.

I really need the sound (i use skype a lot) so any help would be really appreciated.

I have tried all kind of configurations from System -> Preferences -> Sound...
I already reinstalled linux-sound-base, all gstreamer related packages, all alsa related packages, i even downgraded my kernel from 2.6.27-7.16 to 2.6.27-7.14 and nothing...

I have searched and searched all across Google, and can't find anyone that has a similar issue, or a clue on how to reconfigure sound.

dunno what else to do, please some help.

I'm adding a sound recorded from my cell phone near the speaker so you'll get an idea on how it sounds. (what you hear is music playing). You can download it from here http://rapidshare.com/files/164364402/output.ogg

Ahh... btw, under Windows is working fine, so no hardware problems.

lspci:
00:07.0 Audio device: nVidia Corporation MCP67 High Definition Audio (rev a1)

hwinfo --sound :
23: PCI 07.0: 0403 Audio device
  [Created at pci.310]
  UDI: /org/freedesktop/Hal/devices/pci_10de_55c
  Unique ID: M71A.LQQQ2m7P8oE
  SysFS ID: /devices/pci0000:00/0000:00:07.0
  SysFS BusID: 0000:00:07.0
  Hardware Class: sound
  Model: "nVidia MCP67 High Definition Audio"
  Vendor: pci 0x10de "nVidia Corporation"
  Device: pci 0x055c "MCP67 High Definition Audio"
  SubVendor: pci 0x103c "Hewlett-Packard Company"
  SubDevice: pci 0x30d6
  Revision: 0xa1
  Driver: "HDA Intel"
  Driver Modules: "snd_hda_intel"
  Memory Range: 0xfc480000-0xfc483fff (rw,non-prefetchable)
  IRQ: 21 (94674 events)
  Module Alias: "pci:v000010DEd0000055Csv0000103Csd000030D6bc04sc03i00"
  Driver Info #0:
    Driver Status: snd_hda_intel is active
    Driver Activation Cmd: "modprobe snd_hda_intel"
  Config Status: cfg=new, avail=yes, need=no, active=unknown