Scratch sound in Ubuntu 11.10 after OS start

[avi9526]

OS: Ubuntu 11.10
VLC: 1.1.12 (from Ubuntu repository)
1.1.13 (compiled from source)
My problem:
When system just loaded and I run VLC and choose audio file to play, the sound with a very strong noise (very annoying). If minimize VLC to tray (mouse click on VLC icon in tray) and then restore (click again) - sound became normal. Another way to make normal sound - is wait 2 minutes before run VLC (and run other software).

What is it ? How to solve this problem ? Thanks !

[avi9526]

I made a picture using a microphone and Audacity, to illustrate my problem


This problem also appear with VLC 1.1.13 compiled from source.