This thing may be a hardware problem. I used the gentoo livecd so I could
, and the bttv card didn't show up. So I moved it to another PCI slot. It showed up. Rebooted to windows, still nothing. Back to linux, it's gone!
Another reboot, it's back, windows detects it, my two attempts at running dscaler have resulted in (a) the mouse becoming unresponsive and (b) bluescreen.
I'm blaming this on heat, let the machine cool down, try again in a few minutes, all will be as it was before.