I see both of your PCs have SB Live! cards. Try removing them and see if that helps. Live! cards have a very poor PCI bus implementation that VIA chipset boards are particularly intolerant of, especially when you have lots of other cards installed like you do. Creative fixed this problem with the Audigy series (which I haven't tried), but I went with the Turtle Beach Santa Cruz. This is an even bigger problem in Windows, which is where I noticed it. I suspect that one of the RH9 kernel improvements (like the lower latency patch?) increased Shrike's sensitivy to bad hardware.
