This is probably going to be me talking complete c*** (as I don't have, and have never had any TV input on my PC), but if you take a look at the Leadtek site
http://www.leadtek.co.uk/ , there is a connection diagram (click it for an enlarged pop-up) for the PVR2000 (hope that's what you have). It seems to imply that you need to use S-video or composite video to get a signal from your VCR into the card. You may need to use phono leads for the audio with the latter (and maybe the former - never used S-Video). It may be that the card doesn't accept whatever frequency VCR's broadcast on (though that seems unlikely).