mid 2010 iMac won't capture video

Don't know if this is the same issue.

I just got an i7 27" iMac with FCP X for the express purpose of digitizing all of our video.

Sony TRV-310
Apple thunderbolt to 800 fire wire
Belkin Sony I link (4pin FW) to 9 pin (800 FW)

Both FCP and iMovie will display the video in the import screen.
Neither will save the video.

Google search I found that iMovie 6 HD would work.

iMovie 6 indeed imports and saved the video.
But - the format is in compatible with FCP X and iMovie.

I burned the video to a DVD with the apple super drive

That output was in a "mov" format that FCP will not import.

Prior to buying the system I found that the Sony was supposed to be compatible using FireWire.

I'm completely new with the Apple computers and apparently so are the apple store employees when it comes to video.

While I haven't done it in a couple years since replacing my camera with an SD-card based camcorder, I used iMovie to import video off a Sony mini DV tape-based camcorder over FireWire. I honestly don't recall which version of iMovie I used, but it worked perfectly each time.

But like I said, I no longer have the camera (or a FireWire port for that matter), so I can't try it out again.

I found a post somewhere online referencing this issue and a fix of using iMovie HD (version 6 I think).
I found another post of someone that was hosting that version and downloaded/installed.

That allowed the camera to receive and save the video from my Sony Handycam.