I had the same symptoms, scratchy noise when scrolling etc, with an old PC and Windows XP with a SB Live Sound cardI had noticed that the PC was running rather slugish and decided to reinstall Windows, for some reason this fixed the sound scratch. I suspect the sound card drivers or the order in which the drivers were installed, caused the problem. Unfortunately I couldn't recreate the fault to make sure.Seeing your other thread, if the power supply is under 1 year old you should be able to claim warranty on it still. Oh and on second thoughts, rather don't use that same model "cheap" PSU in your computer, I've never heard of fans breaking their fins! It also sounds like there was a ground problem from the PSU, however the 2 faults would seem to be unrelatedHope this helps