Hi again,
did you install xp pro as a acpi or standard pc? It should be standard.The card should have his own IRQ port to avoid internal conflict.With acpi always probs.
Many other laptop users do have probs with internal souncard.
Check-up the bios, AC 97 audio should be disabled. Is there an other onboard soundcard? if so, remove it.
There is nothing else to do than to check things out item after item untill you find the prob. Really hope you'll find the solution, I know all about frustration. So, succes.
chris at www.tsunamimusic.be