I would suggest you get an external USB sound device and forget the internal.
Edirol
Buddy
Extigy
Tornado/Turando
Aka Dell support for laptops.
My brother-in-law got a dell laptop for his business a couple of months ago and it hasn't worked since it arrived. Support has been absolutely appalling throughout and he had to borrow my laptop to get by.
When, eventually, a service engineer turned up he said that: The motherboard was faulty; the software installation was faulty; the keyboard wasn't screwed down properly; he then stated he wasn't even going to attempt to fix it due to it's condition and left.
My brother-in-law is still attempting to obtain a refund. He bitterly regrets he bought it by company cheque rather than credit card and his opinion of Dell is not suitable for printing here.
Needless to say he is now buying one elsewhere.