See here
http://zachd.com/pss/pss.html#audio

Cheers,
Jerry

Useually on a new Laptop or Desktop it usually is a problem with the
electronics. It depends on how the laptop has been used. But it should
be within its warrenty so rather than messing with the hardware and
voiding your warrenty take it back or sent it back. Also bieng a
laptop it is more likley its a hardware fault because of the fact the
most of the circuits are intergrated. I could be a loose wire but
probally best just to sent it back. I little way that can give you an
idea if the computers hardware is alright is when you get it just
leave it running for 48hours and if there is a faulty part or
something that is causing a slight problem, will get worser and you
will realise this quickly. Usually to do this if you have brought a
used PC with a limited warrently to a certian number of days.

could it possibly be a bad sound card from the factory?

I have the same problem!