i have the same exact copies of CF rc2 installed on my desktop, and my carpc.
i am having a volume problem, but its a bit different from what you guys are describing. with mine, i can adjust the volume all the way down to mute even, wait a couple seconds, and then it will gradually start increasing its way to max. it even take it in steps, increasing a bunch, decreasing a little, then increasing more until it gets to max. once its at max i cannot adjust the volume down at all.
the problem is ONLY happening on my carpc. i cannot recreate it on my desktop.