New M1330 audio gone after 3 weeks

I got a new M1330 laptop and after 3 weeks, the audio disappeared completely. No sound from speakers or headphones with any application MediaPlay, CD player, Sound mixer, driver test etc...

I verified that the hardware is working because I can get audio to speakers and head phones if I boot up with MediaHome and play a CD or DVD.

This is most likely a Vista driver issue since the hardware is working.

I deleted the SigmaTel drivers and had Windows update online, reboot and still no audio.

I searched the web and here, and found a few people with similar problems. But their solutions seem to be re-installing the driver which I did a number of times.

I even manually downloaded the SigmaTel drivers for M1330 from Dell and manually deleted and installed the new drivers - nothing.

There is no indication that audio drivers are not working - i.e. no red X. Only when playing a sound or using MediaPlay, does a error message pop up.

Any help appreciated.