Brand new macbook pro, sound not working

A few days ago I bought a my first macbook pro.

I've done all the software updates through software updater, but I cannot get any sounds to play.

None of the volume "pop" noises play when I change the volume, in system preferences it doesn't play previews of the warning sounds. No matter what video player I use it won't play sound. iTunes won't open "Unknown error (-200). Streamed videos also don't have sound.

But strangly when I play games I can hear all the sound in the game, through internal speakers or headphones.

I've searched everywhere but it seems like I'm the only one having this problem!

Please help

Thanks

P.S.
If it's relevant, I bought a new macbook pro 15". I got the 2.2gHz i7 with 1gb graphics and 4gb ram.

Has the sound ever worked? If not, I'd be heading back to the store.

Am only guessing here - the iTunes error indicates it cannot find the audio hardware.

Since the audio is working in some places but not others, thinking I'd try a PRAM reset.

Thanks for the help bobtomay

I do vaguely remember the popping noise working when I changed the volume for the first few times. At that stage I tested streaming videos, obviously I didn't have flash player, after downloading that video sound still didn't work. I don't think flash player is the problem here though.

After that I watched a movie in vlc, and the sound worked.

Could this have something to do with cancelling installing logic halfway through?

I think I successfully reset the PRAM (volume bar went from muted to about 2/3 full) and the chime played when I started up. But unfortunately sound still doesn't work.

What device is set for output in the sound preference panel?

So i've gone into system prefs, sounds, clicked the output tab.
It says Internal Speakers --- Built-in

Sounds about right doesn't it?

And the volume slider there was not set all the way to zero? This will prevent sound from iTunes, Quicktime, system sounds, etc., but would allow it in some games that override any system settings.

If only the slider was set to zero! The slider is set to max, the balance is centred. In the sound effects screen alert volume is set to max and all the boxes are ticked.

Looks like this will take a trip into the shop to get fixed.