Sound card noise on Lenny amd64

[Jose Perez <jvoorhees1@gmail.com>]

Hi people:

I have a Debian Lenny amd64 (up to date) running on a MSI K9A2 Neo2
mainboard. I have sound working without problems when suddenly some
day started to sound badly: I hear a continuous noise like a
'shhhhhhhhhhh' (sorry if it seems funny but i don't know how to
explain this).

This noise happens always on Linux and I have tested against:

- Rebooting
- Disabling/enabling arts
- Turning on/off aplications sound applications (amarok, kmix, kaffeine, etc)
- Removing alsa-utils & alsa-base
- Changing speakers and headsets

I tought my sound card (integrated on the mainboard) got damaged so
before asking for guarantee for my new PC I decided to install
Microsoft Windows and discard problems.
But surprisingly I noted that this noise isn't present at Windows
platform where everything sounds fine, perfect.
This extra information I got:

- When increase os volume (with aumix) the noise get worse, like
something burning up
- When booting my Linux box (at some point of init scripts) the noise
get started
- When halting my Linux box (at some pooint of shutdown init scripts)
the noise disappears
- There's no noise at BIOS or GRUB booting time

I think this is just a Linux problem. Does anybody has any idea?

Thanks and sorry by my bad english