I just upgraded to a pentium 4 2.6C, MSI 865PE Neo2-FISR mobo, and a gig of dual channel Corsair ValueSelect memory. I started overclocking it, and it was good until I hit 216MHz, then I noticed a popping sound whenever audio is played. Back it down to 215, and all is good. I'm using the onboard sound with C-Media sound drivers. Any ideas? I know it can go a bit further than 215MHz, as it's running very cool, about 10 degrees C cooler than my old P4 1.6GHz Willamette in the same case with the same cooler.