This site:

http://72.14.205.104/search?q=cache:...nk&cd=35&gl=ca


has this to say:

"For all users of the dreaded SigmaTel AC97 audio chipset (a lot of notebooks use this), you will be greeted with Microsoft signed Vista drivers when you install the RTM of Vista. However, that joy will fade away quickly: the ever-lasting problem of sound crackling and stuttering will soon make you angry again.

I do not understand why so many notebook manufacturers still keep using/implementing this piece of crap... the only reason I can think of is that it must be really cheap!

Enough whining, here are a few possible fixes:

You can try the RealTek AC'97 drivers for Vista

You can also try the High-Definition Audio Codecs, also from the RealTek website.

You can also scan for SigmaTel drivers on the Dell website ( http://search.dell.com/results.aspx?...Tek&sort=-date ), maybe they'll release a new driver set also. In fact, even the older driver sets from 2005 that you'll find in this list, are more recent than the driver included in Vista. It's not the first time that Dell advises to revert to older SigmaTel drivers because they were far more stable."

It seems in many cases the newer Vista drivers are not operating well and sometimes the older drivers (for older OS's?) will work OK.