ATI 600 USB = no reception at all

[mc510]

So, I threw $25 bucks to woot and got an ATI TV Wonder 600 USB tuner. It works fine on my laptop with Windows 7 (Media Center), but I can't get it to work at all on my XP SP3 desktop (with Sage). I know I'm not the first sucker to have trouble with this tuner, but nothing I've found online has helped me to fix this problem:

The Device Manager claims that the tuner installed correctly and is working, but Sage finds zero channels (digital OTA). I've tried 5 different versions of the ATI drivers; I've tried every possible way of installing; but always zero channels. The exact same antenna, in the exact same location, gets me almost two dozen channels on my Win7 laptop.

Any ideas or suggestions would be helpful; I'm at a dead end.

[MitchSchaft]

Did you look in the list of supported tuners for Sage?

[mc510]

I did; it's listed as VisionTek TV wonder 600 USB (identical to ATI TV Wonder 600 USB).

By the way, I have the same result (zero digital OTA channels) with ATI's own PVR application as well as GB-PVR, so I'm assuming that the problem is not specific to Sage but rather has to do with the XP drivers. All the same, if any sage users have found any secrets to making this thing work under XP, I'm all ears.