ATI TV Wonder USB 2.0 woes

I bought this item six or eight months ago, and I've had it working
just fine at one time, though I do remember it being a little quirky to
get set up.

Anyway, at one point I uninstalled it and all the ATI software during
one of my bouts of PC optimization. I've since tried to reinstall this
piece of hardware and all associated software to no avail. I get no
video or sound out of the TV app. During the initial configuration
wizard, it was able to autoscan and detect all of my cable channels,
but they won't display in the TV window, even though if I flip through
the channels, it does show the channel number it thinks it's playing.

I have completely removed all ATI software (to the best of my ability)
including the display drivers, and tried installing everything straight
off the TV Wonder installation CD as well. When I run the PC Check, it
tells me that I need to install the current version of DirectX, but
it's up to date (v9.0c). It also tells me that the capture drivers need
to be installed even though I've downloaded the current version from
the ATI website and installed them manually.

I'm out of ideas here.