Audio noise when first sound is played built-in Realtek

Hello. I want to ask a question about my problem. I tried to search about my case, but it's seems I'm the only one in this world who has problem like that.

I have Asus P2W DH Deluxe motherboard with buit-in Realtek audio card (ALC882). My 5.1 audiosystem is connected via analog outputs.

A problem is:
When I start PC with Windows 7 Ultimate, first application that plays sound make huge noise to my audiosystem. In background of this noise I can hear quiet sound that must been played. After first noise played the other sounds plays properly. (For example - if you use sound themes - noise will play then your system is starting). Except only one application (only one that I recognize) that doesn't play noise - small mediaplayer AmpView.
This noise plays only with Realtek (I try to use my old SB Live - no noise at all, but SB Live supports only 4.0 audio). And this noise plays only when I use 5.1 mode in realtek (in 2.0 or 7.1 mode - no noise, but I don't want to use 2.0 and I don't have 7.1 audiosystem).
I tried to use different drivers - 2.37 and 2.40. Problem is still exist.
When I used this hardware with Win XP I doesn't have this problem.

Is there someone who has problem like mine? What way I can solve this?

Thank you in advance.

I may have been experiencing a somewhat similar problem. For example, if I play some music and after that leave the computer idle for a couple of minutes, the next time I do anything to produce a sound: starting playback of another song, opening a folder, emptying the recycle bin-I can hear a short, cracking sound just before the sound corresponding to my action.
I am also experiencing a constant sound from the TV card stream in the background, but I can only hear it when I turn up my speakers pretty loud without producing any other sound...
I never managed to find out what's causing this.

Up. Are some decision exists?