Bring Firewire 'fake' DV input to Jitter – error

Hello.

I was able to give and take dv screen capture between two macs by using firewirehub. following way…

http://www.udart.dk/2009/07/30/the-5-video-mixer-how-to-do-a-dv-screen-cast-through-firewire/

but I see error when I use my patch’s jit.qt.grab
It is weird because I can see firewire dv video input with using Quicktime’s Movie recording.

I found out the Quicktime should not running to detect the Firewire input on Jitter,
On Jitter, I see two Firewire selection available, but I don’t see the screen when I select the Firewire input on the list.

Is there any reason that firewire ‘fake’ dv input’s video signal cannot read on Jitter’s grab?
Anyone can help me??

Thank you