I am having a problem trying to convert Hi8 tapes to DVDs using SONY's new VRD-MC3 DVD recorder

I have tested a variety of configurations and the problem seems to be that if the original source material was on a Hi8 tape - the recorder can't sense the signal thru the firewire port

Here are the configurations and results

1. Hi8 tape playing thru Sony TRV460 output via firewire to VRDMC3 - press record on VRDMC3, camcorder starts, plays, VRDMC3 stays with "waiting for signal"
2. Canon ZR10 to VRDMC3 via firewire, using miniDV tape recorded directly on ZR10 - no problem, VRDMC3 records it fine
3. Hi8 tape playing on TRV460 connect to ZR10 via firewire, ZR10 records it fine
4. miniDV tape recorded in #3, playing on ZR10 to VRDMC3 via firewire, VRDMC3 starts the ZR10 playing, then stays with "waiting for signal"

it seems like when the original source was the Hi8 tape , even when converted first to miniDV tape, the VRDMC3 can't pick up the signal

I tried this with 2 different cables and 2 differen VRDMC3's

Any assistance or configuration suggestions appreciated