Any ATI Radeon experts out there? Need help please!

I've got a problem that's driving me nuts! I have an ATI All-In-Wonder
Radeon 7500 that I bought a few years ago for use in my old P3 based
system. I never played around much with the capture capabilities of
the card but now I'd like to use it to transfer some old VHS movies to
DVD. I've installed it on a new P4 system I've put together and all of
the ATI software based stuff works fine including capture.
Unfortunately, no other video authoring proggies can display the video
from the card in their capture modes. They see the ATIWDM Rage Theater
Video device in their settings options but all I get is the audio. I
had this problem when the card was in my old P3 machine and somehow I
fixed it so that I could do captures in Ulead Studio and other
programs, but I didn't write down the solution to the problem that I
stumbled upon quite by accident. Can someone please tell me what I'm
missing? Like I said, the ATI MMC-based functions, including capture,
work just fine. It's only within other programs that I can't see or
capture the card's video output.

Thanks for any and all assistance I can get!

Oz