and33g

I had this problem around a month or two ago with firefox. After searching extensively I believe I found a thread on apple's itunes support page about this issue. Basically for me at least the shuttering would only occur when loading web pages with lots of images after resuming my computer from hibernation mode

The best solution was to update your sound drivers either through Device Manager or from the sound device's website. Actually it may have even been through Dell's integrated update manager because I have a Dell Inspiron 1520

I specifically had the problem with SigmaTel High Definition Audio CODEC however I found an update for the drivers and this fixed the problem. Sorry that I'm a bit scant on details but it was a while ago.

Hope this rambling message was of any use goodluck...it's a pain in the arse I used to cringe every time my music was interrupted

P.S. for some reason the problem has now started again when I use Chrome...any fixes for this one? maybe I should update the drivers again